Power Capacitors COOPER POWER

SERIES
Effective February 2016
MN230001EN Supersedes S230-60-8 October 2013

Type NR oil switch maintenance instructions

NR Switch Family Manufactured in Greenwood, SC

NR CP541000001 through CP541999999

NRV CP542000001 through CP542999999

Notice: This document is also applicable to product serial numbers beginning with the characters CP57.
DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITY
The information, recommendations, descriptions and safety notations in this document are based on Eaton Corporation’s
(“Eaton”) experience and judgment and may not cover all contingencies. If further information is required, an Eaton sales
office should be consulted. Sale of the product shown in this literature is subject to the terms and conditions outlined in
appropriate Eaton selling policies or other contractual agreement between Eaton and the purchaser.
THERE ARE NO UNDERSTANDINGS, AGREEMENTS, WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING WARRANTIES
OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY, OTHER THAN THOSE SPECIFICALLY SET OUT IN ANY
EXISTING CONTRACT BETWEEN THE PARTIES. ANY SUCH CONTRACT STATES THE ENTIRE OBLIGATION OF EATON. THE
CONTENTS OF THIS DOCUMENT SHALL NOT BECOME PART OF OR MODIFY ANY CONTRACT BETWEEN THE PARTIES.
In no event will Eaton be responsible to the purchaser or user in contract, in tort (including negligence), strict liability or other-
wise for any special, indirect, incidental or consequential damage or loss whatsoever, including but not limited to damage or
loss of use of equipment, plant or power system, cost of capital, loss of power, additional expenses in the use of existing
power facilities, or claims against the purchaser or user by its customers resulting from the use of the information, recom-
mendations and descriptions contained herein. The information contained in this manual is subject to change without notice.

ii TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Contents

SAFETY INFORMATION
Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

PRODUCT INFORMATION
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Acceptance and initial inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Handling and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RATINGS AND SPECIFICATIONS

Electrical data (control) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Voltage and current ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

MAINTENANCE
Frequency of maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Periodic maintenance inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

OPERATING INSTRUCTIONS
Electrical operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Manual operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Oil condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Insulation level withstand tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SHOP REPAIR PROCEDURES

Bushings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Moving contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Stationary contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Moving contact arm assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Complete contact box assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Actuator mechanism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Selector and holding switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Actuator assembly replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Greasing recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Head mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

SPARE PARTS AND SERVICE

Type NR/NRV service parts diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Type NR/NRV service parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Actuator and housing service parts diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Actuator and housing service parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 iii

 ! !
SAFETY
FOR LIFE Safety for life SAFETY
FOR LIFE

Eaton meets or exceeds all applicable industry standards relating to product safety in its Cooper Power™ series products.
We actively promote safe practices in the use and maintenance of our products through our service literature, instructional
training programs, and the continuous efforts of all Eaton employees involved in product design, manufacture, marketing,
and service.
We strongly urge that you always follow all locally approved safety procedures and safety instructions when working around
high voltage lines and equipment, and support our “Safety For Life” mission.

Safety information
The instructions in this manual are not intended as a substi- Safety instructions
tute for proper training or adequate experience in the safe Following are general caution and warning statements that
operation of the equipment described. Only competent apply to this equipment. Additional statements, related to
technicians who are familiar with this equipment should specific tasks and procedures, are located throughout the
install, operate, and service it. manual.
A competent technician has these qualifications:
• Is thoroughly familiar with these instructions. DANGER
• Is trained in industry-accepted high and low-voltage safe Hazardous voltage. Contact with hazardous voltage will
operating practices and procedures. cause death or severe personal injury. Follow all locally
approved safety procedures when working around high-
• Is trained and authorized to energize, de-energize, clear,
and low-voltage lines and equipment. G103.3
and ground power distribution equipment.
• Is trained in the care and use of protective equipment
such as arc flash clothing, safety glasses, face shield, hard
hat, rubber gloves, clampstick, hotstick, etc. WARNING
Following is important safety information. For safe installa- Before installing, operating, maintaining, or testing this
tion and operation of this equipment, be sure to read and equipment, carefully read and understand the contents
understand all cautions and warnings. of this manual. Improper operation, handling or
maintenance can result in death, severe personal injury,
and equipment damage. G101.0

Hazard Statement Definitions

This manual may contain four types of hazard statements: WARNING
DANGER This equipment is not intended to protect human
life. Follow all locally approved procedures and safety
Indicates an imminently hazardous situation which, if practices when installing or operating this equipment.
not avoided, will result in death or serious injury. Failure to comply can result in death, severe personal
injury and equipment damage. G102.1

WARNING
Indicates a potentially hazardous situation which, if not WARNING
avoided, could result in death or serious injury. Power distribution and transmission equipment must
be properly selected for the intended application. It
CAUTION must be installed and serviced by competent personnel
who have been trained and understand proper safety
Indicates a potentially hazardous situation which, if not procedures. These instructions are written for such
avoided, may result in minor or moderate injury. personnel and are not a substitute for adequate training
and experience in safety procedures. Failure to properly
CAUTION select, install or maintain power distribution and
transmission equipment can result in death, severe
Indicates a potentially hazardous situation which, if not personal injury, and equipment damage. G122.3
avoided, may result in equipment damage only.

iv TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Product information Handling and storage
Be careful during handling and storage of the switch to min-
imize the possibility of damage. If the switch is to be stored
for any length of time prior to installation, provide a clean,
Introduction dry storage area.
Service Information MN230001EN covers the maintenance
instructions for Eaton's Cooper Power™ series Type NR
electrically-operated, single-phase, oil switches. This
Standards
includes their general description, operating principles and
instructions for periodic inspection and shop repairs. Service Type NR oil switches are designed and tested in accordance
parts lists, keyed to exploded-view drawings of the switch, with IEEE Std C37.66™-2005 standard.
are included at the back of the manual.
Type NR oil switches are single-phase, electrically-operated Quality standards
with a quick-close, quick-open mechanism which also
provides the switch with close-and-latch capability. ISO 9001 certified quality management system

The switches are electrically operated. The standard actuator

can be operated by any three-wire control device employing
a set of SPDT contacts. Description of operation
Read this manual first With the main switch contacts closed, energizing the
opening circuit will operate the actuator motor to release
Read and understand the contents of this manual and follow a toggle which allows the preloaded opening springs to
all locally approved procedures and safety practices before snap open the switch contacts and load the closing spring.
installing or operating this equipment. It also drives the cam to position the selector switch for
a closing operation and interrupts the opening circuit to
stop the motor. The opening circuit must remain energized
Additional information for at least 4.0 seconds for the actuator to perform these
These instructions do not claim to cover all details or functions.
variations in the equipment, procedures, or process With the main switch contacts open, energizing the
described, nor to provide directions for meeting every closing circuit will operate the actuator motor to allow the
possible contingency during installation, operation, or preloaded closing spring to snap closed the switch contacts
maintenance. For additional information, contact your Eaton and load the opening spring. It also drives the cam to
representative. position the selector switch for an opening operation and
interrupts the closing circuit to stop the motor. The closing
circuit must remain energized for at least 0.5 seconds for
Acceptance and initial inspection the actuator to perform these functions.
Each Type NR oil switch is completely assembled, tested,
A holding switch accessory installation in the actuator
and inspected at the factory. It is carefully calibrated,
reduces to one second the minimum time the control must
adjusted and in good condition when accepted by the
be energized to effect an opening or closing operation.
carrier for shipment.
Upon receipt, inspect the carton for signs of damage.
Unpack the switch and inspect it thoroughly for damage
incurred during shipment. If damage is discovered, file a
claim with the carrier immediately.

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 1

Ratings and specifications

Table 1.  Electrical Data (Control)

Description Rating
Nominal operating voltage (Vac) (50/60 Hz only) 120 240
Operating voltage range (Vac) 95 – 130 190 – 260
Closing-motor current (amp) 1.9 .7
Switch response time, opening (sec) 4.0 4.0
Switch response time, closing (sec) 0.5 0.5

Table 2.  Voltage and Current Ratings

15 kV with 15 kV with
Description Standard 17" Creepage 125 kV BIL 22 kV
Maximum Design Voltage, kV 15.0 15.0 15.0 22.0
Nominal Operating Voltage, kV 2.4-14.4 2.4-14.4 2.4-14.4 20.0
Basic Insulation Level (BIL), kV 95 95 125 125
60 Hertz Withstand Voltage, kV
Dry, One Minute 35 35 42 60
Wet, Ten seconds 30 30 36 50
Continuous Current Rating, Amps 200 200 200 60
Load Interrupting Ability (Inductive), Symmetric Amps
75-100% power factor
50-75% power factor 200 200 200 60
< 50% power factor 100 100 100 60
50 50 50 60
Maximum Capacitive Current, Amps (parallel bank-max) 200 200 200* 60*
High Frequency Transient Current, Amps 12000 12000 12000 12000
Transient Frequency, Hz 6000 6000 6000 6000
High Frequency Damping Factor .40-.55 .40-.55 .40-.55 .40-.55
Momentary Rating, Amps asym. 9000 9000 9000 9000
Short Time Current Amps
1/2 second,sym. 6000 6000 6000 6000
1 second, sym. 4500 4500 4500 4500
Close and Latch Rating, Amps asym. 9000 9000 9000 9000
*The 125 kV BIL switch and the 22.0 kV switch are rated for single bank switching only.

2 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Maintenance
Terminals
Lifting
Frequency of maintenance Strap
These switches are applied under widely varying operating
and climatic conditions, therefore, maintenance intervals Cover--
are best determined by the user based on actual operating Clamped
Bushings Sleet
experience. To assure proper operation, switches must
Hood
be maintained when they have performed the equivalent
of a complete operating duty cycle and before the Head
dielectric strength has deteriorated below prescribed Casting
levels. In the absence of specific operating experience,
Eaton recommends the switch be inspected and serviced
every 1200 operations or three years, whichever comes
first. In no case should the service interval, between
periodic maintenance and inspection, extend beyond 1200
Operating
operations. Lever

CAUTION
Contact
This equipment requires routine inspection and Structure
maintenance to ensure proper operation If it is not
maintained, it can fail to operate properly. Improper
operation can cause equipment damage and possible
personal injury. G105.1

Periodic maintenance inspection Actuator

Each periodic maintenance inspection should include at Housing
least the following: Stationary Moving Contacts
Contacts
1. By-pass and remove the switch from service.
2. Inspect external components. Figure 1.  Untanked Type NR oil switch.
A. Clean the bushings and inspect for chips, cracks
and breaks. Replace as necessary, following proce-
dure in "Shop Repair Procedures—Bushings" sec- Operating Shaft Drive Lever
Pin
tion.
B. Check for paint scratches and other mechanical
damage. Paint to inhibit corrosion.
Elastic Stop Nut
3. Perform a dielectric withstand test to determine the
insulation level. Follow procedures in "Insulation Level
Drive Motor
Withstand Tests" section.
4. Loosen the head bolts and remove the mechanism
from the tank. Be careful not to damage the gasket
if the tank and head must be pried apart to break the
seal.
5. Allow the oil to drain off the mechanism. Drive Lever
Selector Switch

Black Selector
White Motor Lead To Switch Lead To
Terminal G Terminal 3

Red Selector Switch Closing Spring

Lead To Terminal 2

Terminal Strip For

Customer Connections 5 Pin / 3 Conductor Or
6 Pin / 6 Conductor
Receptacle
Figure 2.  Standard actuator mechanism with auxiliary
switch option.

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 3

 13. Install new tank wall liners and fill the tank with clean,
CAUTION new insulating oil to within one inch of the top of the
tank flange. Oil capacity is approximately 1.5 gallons.
Dielectric failure, equipment damage. Never use volatile
solutions, detergents, or water-soluble cleaners when NNote: Use only new, or like-new reconditioned transformer
cleaning the interior of this equipment. These cleaners oil which conforms to the specifications in Reference
will contaminate the insulating oil, reducing its dielectric Data R280-90-1, Oil Specifications and Test.
strength. Operation with contaminated insulating
oil can result in internal flashovers that will cause 14. Replace all external seals and gaskets.
equipment damage and possible personal injury. T201.2
15. Clean the head gasket seat and retank the switch.
A. Replace the head bolts and torque to 15 ft-lbs.
6. Clean the internal components: Apply clamping force gradually and equally, in rota-
A. Remove all traces of carbon by wiping with a clean tion, to each bolt to achieve an evenly distributed
lint free cloth. Flush the mechanism with clean, dry gasket sealing pressure.
transformer oil. 16. Electrically operate the switch to check for proper oper-
B. If additional cleaning action is necessary, a ation. See "Operating Instructions—Electrical Operation"
dielectric cleaner (Biogenic® Electrosafe from section.
Rochester Midland, Positron Dielectric Cleaner, or 17. Repeat the high voltage dielectric withstand test (Step
similar) may be used to clean internal parts. Check 3) to make sure the dielectric clearances within the
with your local regulating authorities to determine tank have not been compromised.
which dielectric cleaners are permitted in your area.
After the cleaner has evaporated, the mechanism
must be thoroughly flushed or dipped in clean, dry Operating instructions
transformer oil to remove all cleaner residue. Even
dielectric cleaners with high dielectric strength
leave a residue that will affect oil insulating
properties if not removed.
Electrical operation
The switch may be opened and closed electrically by
7. Check the moving and stationary contacts. applying rated control voltage to the proper terminals of the
actuator terminal block. Figure 3 illustrates a connection
A. Dress slight pitting and discoloration with crocus cloth. diagram for a standard three-wire control.
B. Replace both the moving and stationary contacts
if they are severely eroded. Follow procedures in
"Shop Repair Procedures—Contacts" section.
Closing: Approx. 1.5 sec
NNote: The contacts should be replaced before the erosion Opening: Approx. 4 sec
of the load current transfer surfaces impairs their
effectiveness.
AC-White, DC-Black
8. Manually close and trip the switch several times to
check that all components perform properly. AC-Black, DC-Red
SEL
9. Inspect tank lines. Note that two liners are employed. SW.
The inner liner is fibrous and readily absorbs any
moisture present. Soft or spongy areas indicate water MOTOR NO
NC
has been absorbed. Replace the liner if such areas are
C
present. The outer liner need not be replaced unless it
is cracked or punctured.
10. Check the dielectric strength of the insulating oil.
A. A sample taken near the bottom of the tank should Black
have a dielectric strength of not less than 22 kV. Red
B. Low dielectric strength indicates the presence of
water or carbon deposits; replace the oil. (See "Oil
Condition" section.) NOTE: G=Ground
2=Close
0 1G 2 3 4 3=Open
11. If oil must be replaced, drain the tank and discard the
tank wall liners.
12. Thoroughly clean out all sludge and carbon deposits Figure 3.  Typical connection diagram for three-wire
and rinse the tank with clean oil. control.

4 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Manual operation Test 1: Proceed as follows:
The switch may be manually opened and closed by operat- 1. Close the switch.
ing the yellow handle under the sleet hood.
2. Ground switch tank and head.
NNote: Manual operation does not affect the status of the
electrically operated actuator. To electrically close 3. Apply proper test voltage to one of the bushing
a switch which has been manually opened, the terminals.
electrical open circuit must be first activated to •• The switch should withstand the test voltage for 60
change the status of the selector switch for a close seconds.
operation.

Test 2: Proceed as follows:

Oil condition 1. Open the switch.
Oil plays an important role in the proper functioning of 2. Ground switch tank and head.
the switch. It provides the internal insulating barrier from
phase to ground, and acts as an arc quencher. Switching 3. Ground the bushing on one side of the switch.
operations cause reductions of some of the oil into 4. Apply proper test voltage to the ungrounded bushing.
chemical compounds, free carbon and gases. Some of
these compounds form water-absorbing particles which •• The switch should withstand the test voltage for 60
reduce the dielectric strength of the oil. For effective switch seconds.
operation the oil must be replaced before it deteriorates
below a safe level. Oil that has been contaminated with 5. Reverse the test and ground connections to the
carbon sludge or has a dielectric strength of less than 22 kV bushings.
should be replaced. 6. Again apply proper test voltage to the ungrounded
Used oil must be reconditioned before using. Filtering may bushing.
remove absorbed and free water, and other contaminants to •• The switch should withstand the test voltage for 60
raise the dielectric strength to an acceptable level. However, seconds.
it does not always remove water-absorbing contaminants.
Thus, the dielectric strength of the oil may fall rapidly after
the switch is returned to service. Therefore the switch Test results:
should be filled with new oil or oil that has been restored to These high potential withstand tests provide information on
like-new condition. Oil used in these switches conforms to the dielectric condition of the switch.
ASTM Standard D3487, Type 2; its property limits are listed
in Reference Data R280-90-1, Oil Specifications and Tests. 1. If the switch passes the closed-contacts test (Test 1)
but fails the open-contacts test (Test 2) the cause is
New oil should always be filtered before using even likely to be in the main contact assembly.
though it is obtained from an approved source. Passing oil
through a blotter press will remove free water and solid 2. If the switch fails the closed-contacts test (Test 1) the
contaminants such as rust, dirt, and lint. When filtering cause is likely to be a diminished electrical clearance or
the oil, aeration should be kept to a minimum to prevent failed insulation.
moisture in the air from condensing in the oil and lowering 3. After correcting the problem, retest to confirm the
its dielectric strength. repair.

Insulation level withstand tests

High-potential withstand tests provide information regarding
the dielectric condition of the switch. Testing is performed at
75% of the rated low-frequency withstand voltage (Table 3).

Table 3.  Test Voltages for Insulation Level Withstand

Test
Switch Type BIL (kV) Test Voltage (kV)
NR 95 35.0
NR* 125 42.0
* Extra creepage bushings

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 5

Shop repair procedures
Aluminum Clamping
The operations described in this section should be Ring
performed under the cleanest conditions possible. The
repair work, except for bushing replacement, will be
simplified if the work bench is arranged so the mechanism/
head assembly can be inverted (bushings down). No special
tools are required for any of the repair procedures.

Bushings
Bushing maintenance generally consists of a thorough
cleaning and a careful examination for chips, cracks, or Bushing
other mechanical damage during the periodic maintenance Gasket
inspection. Bushings must be replaced whenever damage is
discovered. Bushing
Clamp
The Type NR oil switch bushings are oil-filled. The special
fixtures and procedures required to assemble these
bushings is beyond the scope of normal shop maintenance
repair. Therefore if a bushing is in any way damaged, the
complete bushing assembly must be replaced. Refer to
Figure 8 and proceed as follows:
1. Disconnect the appropriate bushing lead from the
bottom end of the bushing rod.
Figure 4.  Bushing removal.
2. Remove the three hex head capscrews and bushing
clamps that secure the bushing to the head casting and
lift out the complete bushing assembly.
3. Remove and discard the lower bushing gasket.
4. Twist off the split aluminum ring from the old bushing
and install on the new bushing assembly if ring is in
good condition; replace ring if damaged.
NNote: The clamping ring cushions and distributes the
pressure between the porcelain and the clamps. DO
NOT OMIT.
5. Install the new bushing assembly into the head using
a new lower bushing gasket. Position the bushing with
the stud-end of the terminal pointing outward.
6. Position the clamping ring with the split centered
between two clamping bolts.
7. Reassemble the bushing to the head casting. Tighten
the clamping bolts evenly, a little at a time, to a torque
of 3-7 ft-lbs.
NNote: Clamping forces must be applied gradually and Stationary
equally, in rotation, to each bolt. This results in an Contacts
evenly distributed gasket pressure.
8. Reconnect the lead to the bushing rod.

Contacts
The Type NR oil switch has an open-type, double-break
Moving Contacts
contact arrangement as shown in Figure 6. Depending
upon the extent of damage, the stationary and moving
Figure 5.  Open-type double-break contact arrangement of
contacts only, the moving contact and arm assembly, or the
Type NR oil switch.
complete contact box assembly may be replaced.

6 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

 Contact resistance*
Contact Retaining Standard: 750-875 mΩ
Screws Extra Creepage (17 inch): 875-1000 mΩ
20 kV (125 kV BIL): 845-945 mΩ

Moving contacts
Minor pitting can be smoothed with crocus cloth. If contacts
Moving Contact show appreciable wear due to arc erosion, replace as
Arm
follows:
1. Remove the round head screws and lockwashers that
secure the moving contact bar to the contact arm.
Contact Bar Remove the bar from the contact arm.
2. Reassemble the new moving contact bar to the
contact arm and secure with round head screws and
lockwashers. Apply one drop of Loctite® Threadlocker
242® to each threaded hole of the contact bar prior to
assembly.

Stationary contacts
Smooth minor pitting with crocus cloth. If contacts are
excessively eroded, replace as follows:
Figure 6.  Removing moving contact. 1. Remove hex nut, lockwasher and flatwasher from
contact stud. Loosen nut on bushing rod slightly and
slip terminal lead from contact stud.
2. Open flexible contact leads and remove contact
retainer. Pull the stationary contact assembly and
contact roller from contact stud.
Stationary Contact
Assembly 3. Install contact roller within new contact assembly and
mount on the contact stud. Install following parts in
order: contact retainer, flexible contact leads, terminal
leads, flatwasher, lockwasher and hex nut. Tighten hex
nut on bushing rod.
4. With the moving contacts in the open position, the
space between the stationary contacts should measure
0.281 ± 0.010 inch.
Contact Retainer
NNote: The stationary contact assembly is normally pre-
adjusted during manufacture to obtain this clearance.
Bend the contact fingers as required if this spacing is
not within specified tolerances.
Contact Stud
CAUTION
Flexible Contact
Be sure not to pull contacts or contact structure out
Lead of alignment when tightening the jumper lead to
the bushing terminal rod. To test alignment, wet the
contacts with oil. Then, with the actuator mechanism
prepared for a closing operation, push the contacts
closed by hand and hold for a few seconds. When the
moving contacts are released, they should be pulled
open by the spring in the head mechanism. If not,
adjust stationary contacts as described in Step 4 until
they do so.
Figure 7.  Removing stationary contact.

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 7

Moving contact arm assembly 5. Reassemble the new contact arm assembly, which
includes the moving contact bar, to the contact box.
To replace the moving contact arm assembly proceed as
follows:
1. Detach both opening springs from toggle link (Figure 8).
2. Pull back latch lever assembly and remove C-ring which
secures the toggle link to the bell crank lever.
Moving
NNote: The latch assembly can be held back with a Contact Bar Contact Arm
screwdriver as shown in Figure 9. Assembly

3. Remove the pivot pin attaching the contact arm Measure

assembly to the side plates of the contact box. 1/16 "
4. Remove the contact arm assembly.

Opening Springs

Toggle link

Support Arm Operating Link

C-Ring

Bell Crank
Lever
Latch Lever

Figure 10.  Contact engagement adjustment (stationary

contact removed to show measuring point).

Hex Head Machine

Screws

Figure 8.  Components of toggle mechanism assembly.

Screwdriver

Figure 9.  Holding back latch lever with screwdriver.

Figure 11.  Contact structure removed from head
mechanism.

8 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

6. With the mechanism closed, the moving contacts Pin Operating Shaft Drive Lever
should be within 1/16-inch of full engagement, as
measured between the top edge of the moving contact
insulator and the bottom edge of the contact box side
plate as shown in Figure 10. To obtain this dimension, Elastic Stop Nut
adjust the effective length of the insulated operating
link by adjusting the attaching point for the contact
arm assembly in the slotted hole of the link. Be sure Drive Motor
to retighten the elastic stop nut when adjustment is
completed.

Complete contact box assembly

To replace the complete contact box assembly proceed as Drive Lever
follows: Selector Switch

1. Detach the opening springs and disconnect the toggle

link from the bell crank as described in "Moving Contact Black Selector Switch
White Motor Lead To Lead To Terminal 3
Arm Assembly" section, Steps 1 and 2. Terminal G
Closing Spring
2. Remove the hex nuts, lockwashers and flatwashers Red Selector Switch
Lead To Terminal 2
that retain terminal leads to bushing rods.
3. Remove four hex head machine screws with pre-
assembled lockwashers that secure the contact Terminal Strip For
Customer Connections 5 Pin / 3 Conductor Or
structure to the head casting. Contact structure 6 Pin / 6 Conductor
removed from switch is shown in Figure 11. Receptacle

4. To replace contact structure:

Figure 12.  Standard actuator mechanism with auxiliary
A. Slip toggle link over bell crank lever and secure switch option.
with C-ring.
B. Attach contact structure to head casting with hour
hex head machine screws with lockwashers.
C. Attach opening springs to toggle link. S-3
2
D. Install moving and stationary contact assemblies, if
necessary, as described previously. S-1 S-2 S-3
2 1 1
E. Attach terminal leads to bushing rods with flat- M
washers, lockwashers and hex nuts.

S-1
Actuator mechanism SA
1
The actuator mechanism requires little attention. When the
switch is removed from service for its periodic maintenance
inspection, check the condition of the selector switch
0 1 G 2 3 4
contacts, and holding switch contacts if so equipped. + + + + +
Also check the condition of the wiring, motor and cams.
Components of a standard actuator mechanism are shown Legend
0 Auxiliary Circuit
in Figure 12. Figure 13 shows the wiring diagram of the 1 Holding Circuit
switch actuator with the various accessory connections G Ground
shown in dotted lines. 2 Closing Circuit
3 Opening Circuit
4 Auxiliary Circuit
M AC Motor
S-1 Selector-switch opening-circuit contacts
1
S-1 Selector-switch closing-circuit contacts
2
S-3 Auxiliary switch actuated directly from main shaft
SA Surge arrester

Figure 13. Wiring diagram with accessory connections

indicated by broken lines.

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 9

Selector and holding switches
To replace the selector switch, or holding switch if so
equipped, proceed as follows:
1. Heat the solder joint at the common terminal of the
selector switch to disconnect black lead (Figure 12).
Use a gun rated no higher than 100 watts and use only
50-50 or 40-60 rosin core solder for repair work.
Cam
2. Disconnect leads from terminal strip: red and black
from terminals 2 and 3 for selector switch, green from Selector Switch
terminal 1 for holding switch. Contact and
Over-travel Cam
3. Remove two round head screws with lockwashers that
secure the switch to the support bracket. Mounting
spacers and a nut bracket (on underside of support) will Selector Switch
also be released.
4. Attach new switch to support bracket, securing it
loosely with two round head screws so that it is free to
move for adjustment.
5. Connect wire lead(s) to terminal strip. Solder black
lead(s) to common terminal of selector switch.
6. Operate cam electrically and adjust selector switch so Figure 14.  Adjustment procedure for selector (main
contact actuation takes place relatively early on cam contacts and spring relaxed).
lobe, and that an over-travel (movement of operator arm
after contact actuates) of approximately 3/64-inch is
achieved.
7. Check that main contacts open before the selector
switch actuates. Main contact and selector switch are
properly coordinated when an audible click is heard,
from within the tank, before selector switch contact
actuates.
8. Adjust holding switch (if so equipped) so actuation
takes place after selector switch actuation and operator
arm over-travel is observed. A definite time lag between
the actuation of the selector switch and holding switch
must be observed.
NNote: It may be necessary to readjust selector switch to
obtain proper sequence and over-travel.
9. When selector switch and holding switch (if so
equipped) are properly adjusted, tighten screws to
secure switch(es) to support bracket. Run actuator
through 25 opening and closing operations to be sure
switch adjustments hold.

10 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Actuator assembly replacement Head mechanism
To replace the actuator assembly proceed as follows: The head mechanism requires no periodic maintenance.
Observe the following procedure when disassembling the
1. Pull yellow handle down to open switch contacts. head mechanism:
2. Remove elastic stop nut, lockwasher and flatwasher 1. Remove the contact structure as described in "Shop
from operating shaft. Repair Procedures—Complete Contact Box Assembly"
3. With a right angle punch or allen wrench force out section.
straight pin as shown in Figure 15. 2. Remove the bushings as described in "Shop Repair
4. Disconnect wire leads from terminal strip. Procedures—Bushings" section.

5. Remove four screws that secure actuator base plate to NNote: This step is not mandatory, but is suggested to
housing. Carefully lift actuator assembly from housing, simplify working on the head mechanism if a service
pulling the drive lever straight from the operating shaft. rack is not available.

6. Place actuator assembly in mounting position and slip 3. Perform Steps 1 and 2 in "Actuator Assembly" section
drive lever over operating shaft. Loosely install the four to free the actuator mechanism from the operating
mounting screws that secure the base plate to the shaft.
housing. 4. With a hammer and punch, drive out the roll pin that
7. Insert straight pin through drive lever and operating secures the reset lever to the operating shaft (Figure
shaft. Install flatwasher, lockwasher and elastic stop 16).
nut. Tighten stop nut firmly to prevent straight pin from
backing out. Moderate force is sufficient to tighten stop
nut. Extreme force on nut can break straight pin.
8. Tighten four actuator assembly mounting screws.
9. Attach wire leads to terminal strip, as shown in Figure
12.
10. Operate the switch electrically and check for binding.
Check adjustment of selector switch (and holding
switch if equipped) as described in "Shop Repair
Procedures—Selector and Holding Switches" section.

Greasing recommendations
When a Type NR oil switch is removed from service, check
these points in the actuator for sufficient lubrication:
•• Spring anchor boss
•• Actuator drive lever spring anchor
•• Mechanism shaft through cam center
•• Pinion gear on motor shaft and mechanism gears
Apply “MOBILGREASE 28” or a similar low-temperature
grease to these areas. Well-lubricated mechanisms will
reduce subsequent wear and preserve smooth actuator
operation.
NNote: Grease need only be applied to these points when
the switch is removed from service. Do not remove Figure 15.  Removing straight pin with allen wrench.
switch from service for sole purpose of applying
lubrication to the actuator mechanism.
5. Remove the sleet hood cover and slip the operating
handle spring from the reset lever. Slide out the
operating shaft.
6. Install new parts as required. Be sure roll pin that fixes
reset lever to operating shaft is driven in until 3/16-inch
of pin projects as shown in Figure 16.

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 11

7. To replace the latch lever assembly:
A. Remove screws that secure the shaft retainers to
the head casting.
B. Lift out the latch lever assembly.
C. When reassembling, slip the latch lever torsion
spring and latch lever onto the latch lever shaft.
D. Screw the two shaft retainers to the head casting
to secure the latch lever shaft.
E. Hook the torsion spring on the latch lever assem-
bly. Be sure the two shaft retainers are positioned
as in Figure 17, and that the latch lever is retarded
when moved away from the head casting.

8. Install the contact structure and bushings to complete

assembly.

Operating Shaft
Spring
Holes in Shaft
Retainers
Reset Lever

Operating Shaft
Figure 17.  Correct position of shaft retainers.
Roll Pin

Bell Crank

Shaft Retainer Spring

Anchor

Latch Lever

Torsion Spring

Figure 16.  Components of head mechanism assembly.

12 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

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TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 13

Service parts list

Figure 18. Type NR oil switch service parts.

14 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Type NR oil switch service parts
Item Item
No Description Catalog Number Qty No Description Catalog Number Qty
1 Bushing assembly, Type NR Standard GRA0346003 2 32 Toggle spring GS00040 2
Bushing 33 Shock absorber GR00107 1
2 Bushing assembly, Type NR 17" GRA0346005 2 34 Self-tapping screw, rd hd, Type F, 4-40 753315106062A 2
Creepage Bushing x 5/16 stl
3 Capscrew hex hd, 5/16-18 x 1-3/8, stl 730115131150A 6 35 Screw, hex hd, with pre assembled 830101131050A 4
4 Lifting strap H000472 1 split lockwasher,5/16-18 x 1/2,
5 Bushing clamp GR00233 6 Parkerized
6 Clamping ring, Aluminum GR00110 2 36 Contact box assembly GRA0385 1
7 Bushing gasket KA20900040 2 37 Hex nut 1/4-20, brass 881025120025A 2
8 Plain washer #20S, brass 900525033075A 2 38 Split lockwasher, med, 1/4 bronze 900830025000A 2
9 Split lockwasher, med, 5/16, bronze 900830031000A 2 39 Plain washer, #14S, brass 900525026056A 2
10 Nut, Hex, 5/16-18, brass 881025118031A 2 40 Terminal lead GR00257 4
11 Capscrew, hex hd, 5/16-18 x 1-3/8 stl 730115131137A 4 41 Contact retainer GR00214 2
12 Lockwasher, 5/16 stl 900815031000AGW 4 42 Contact assembly GN3A0000640002 2
13 Clamp 6A00326401 4 43 Contact roller GR00256 2
14 Head casting GR00330 1 44 Capscrew, hex hd, 1/4-20 x 1-1/4 730125125125A 2
brass
15 Shaft insert KA30360019 1
45 Moving contact arm assembly GR00326 1
16 Head gasket KA21030012 1 (includes items 49, 50, and 51)
17 Caution plate SI01057 1 46 Pin KA31230011 1
18 Control rating plate, Decal 6A00471702 1 47 Plain washer, #10S, brass 900525020043A 2
19 Screw, sheet metal, Type Z, #2 x 3/16 Not required for Decal 4 48 Retaining ring 970901188000M 2
20 Nameplate GR00122 1 49 Machine screw, rd hd, #6-32 x 1/2, sst 721515106050A 2
21 Self-tapping screw, rd hd, Type Z #10 802815010037A 2 50 Lockwasher, Internal tooth #6 bronze 901032006000A 2
x 3/8
51 Contact bar GRA0384 1
22 Operating handle assembly GRA0033001 1
52 Tank liner GR00115 1
23 Reset lever GSA0009 1
53 Tank liner NRV GR00289 1
24 Roll pin KA20010030 1
54 Bottom liner GR00114 1
25 Bell crank assembly GRA0040001 1
55 Tank Assembly GRA0021003 1
26 Operating handle spring GR00296 1
56 Parallel ground clamp Ground clamp HA00227 1
27 Latch lever GSA0078 1 assembly
28 Latch lever spring GS00011001 1 57 Capscrew, hex hd 1/2-13 x 1, stl 730115150100A 1
29 Latch lever pin KA30540002 1
30 Pin retainer and spring anchor GR00120 2
31 Machine screw, rd hd, with pre- 831501125037A 2
assembled split lockwasher 1/4-20 x
3/8, stl
The service parts and hardware listed and illustrated include To assure correct receipt of any part order, always include
only those parts and assemblies usually furnished for repair switch type and serial number. Because of Eaton's
or involved in the maintenance procedures described in continuous improvement policy, there may be instances
this manual. Further breakdown of listed assemblies is not where the parts furnished may not look exactly the same
recommended. as the parts ordered. However, they will be completely
interchangeable without any rework of the switch.
Dimensions of all common hardware parts have been
carefully checked so that they may be locally acquired. The
suffix letter of the 14 character catalog number of common
hardware parts code the plating of the part:
A - No plating; raw material
H - Silver
M - Black oxide
Q - Cadium + zinc + chromate
Y - Zinc + chromate
Z - Electro zinc + bronze irridite

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 15

Figure 19.  Actuator and housing service parts.

16 TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016

Actuator and housing service parts
Item
No Description Catalog Number Qty
1 Machine screws, Fil hd. #10-24 x 7/8 sst 999904250369A 8
2 Cover GR00323 1
3 Gasket GR00121 1
4 Nut KA20200003 1
5 Split lockwasher, med, 1/4 bronze 900830025000A 1
6 Plain washer, #14S, brass 900525026056A 1
7 Switch Assembly * 1
Limit Switch KA23980002
Holding KA23980001
Auxiliary (SPDT) GRA0364
8 Spacer GR00324 1
9 Screw, pan hd mach #10-24 x 1-1/2 sst 721715110150A 1
10 Terminal strip GR00266 2
11 Screw, self-tapping, phillips, pan hd, Type F, 753315106062A 1
#6-32 x 5/8, sst
12 Actuator (includes item 13 and standard GRA0381 1
selector switch)
Actuator repair kit, 240 Vac (includes item GRA0321
13 and standard selector switch)
13 Spring GR00302 1
14 Vent screen plug GR00038001 1
15 Pin KA30540002 1
16 Machine screw, Fil hd #1/4-20 x 3/8 stl 723101125037Z 3
17 Housing GR00319001 1
18 Oil seal GR00275 1
19 Motor, 110V GR00320 1
Motor, 240V GR00321
20 Receptacles ** 1
5 Pin/3 Conductor GRA0121005
6 Pin/6 Conductor GRA0108002

* Sold separately
**Not shown in the illustration shown on page 16

TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 17

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TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016 19

 !
SAFETY
FOR LIFE

Eaton
1000 Eaton Boulevard
Cleveland, OH 44122
United States
Eaton.com

Eaton’s Cooper Power Systems

Division
2300 Badger Drive
Waukesha, WI 53188
United States
Eaton.com/cooperpowerseries

© 2016 Eaton Eaton is a registered trademark.

All Rights Reserved For Eaton's Cooper Power series product
Printed in USA All trademarks are property information call 1-877-277-4636 or visit:
Publication No. MN230001EN of their respective owners. www.eaton.com/cooperpowerseries.