Ecodial Advance Calculation 4.1 PDF
Ecodial Advance Calculation 4.1 PDF
Ecodial Advance Calculation 4.1 PDF
Technical help
Ecodial Advance Calculation 4.1
Contents
Main changes following the Cenelec TR50480 report
Types of system earthing
Types of transformer losses
Diversity factor Ks
Switchgear status and operating modes
Discrimination of protective devices
Check on the thermal stress in cables
Discrimination of residual-current protective devices
Cascading
Withdrawable circuit breakers and switches
Electrical operating mechanisms for circuit breakers and switches
Remote opening of switches
Visible break
Classification of residual current devices
Implementing residual-current protection
Highly sensitive residual-current protection
Medium-sensitivity residual-current protection
Maximum permissible voltage drop for loads
Circuit voltage-drop tolerances
Cable installation method
Maximum, permissible cross-sectional area
Third-order harmonic distortion
Manual and alternate solutions
Additional derating coefficients for wiring systems
Waiver of overload-protection requirements for safety circuits
Power factor for short-circuits on LV sources
Calculation of LV-source phase impedances, based on Ik3max
Calculation of LV-source neutral impedances, based on Ik1min
Calculation of LV-source PE impedances, based on Ief
Calculation of LV-source PE impedances, based on Ief2min
Consistency of LV-source input parameters
ZT
ZSUP ZC ZG ZSUP Z Q Z C ZQ ( ZT ZC ) ZQ ( ZT ZC )
Incomer: ZSUP Outgoer: ZSUP
nT 1 nT
nT is the total number of transformers operating
simultaneously.
Incomer = the conductor between the transformer and the
main switchboard.
Outgoer = the circuits supplying the entire installation
downstream of the main switchboard.
Rb
TN-C system
Rb Ra
TT system
Rb Ra
IT system
Ra
Dry-type transformers
Dry-type encapsulated transformers offer two possible loss levels:
normal losses,
reduced losses.
Diversity factor Ks
Standard IEC 60439-1 defines the diversity-factor (Ks) values that may be used if more precise
information on switchboards and busbar-trunking systems (BTS) is lacking.
Ecodial uses these values by default to calculate the design currents for BTSs and busbars.
Switchboard busbars
Number of outgoers Ks
1 1
2-3 0.9
4-5 0.8
6 to 9 0.7
10 and more 0.6
Distribution BTS
Number of outgoers Ks
1 1
2-3 0.9
4-5 0.8
6 to 9 0.7
10 to 40 0.6
Over 40 0.5
When a part of the network is not supplied in a given operating mode, it is shown in blue in the single-
line diagram. Given that the "closed" status condition is the most common in installations, only the
"open" status condition is shown in the single-line diagram.
Tripping curve
Non-tripping curve
If the selectivity limit current is lower than the short-circuit current that can occur on the circuit
protected by the downstream protective device, discrimination is said to be partial.
If the selectivity limit current is higher than the maximum short-circuit current that can occur on the
circuit protected by the downstream protective device, discrimination is said to be total for the given
installation.
If the discrimination limit is in the table zone, the rating of the upstream protective device must be
increased. In this case, Ecodial retains the circuit design current Ib as the reference for the thermal
setting of the protective device to avoid oversizing the cable.
Ikmin
i²t phase
i²t neutral
i²t PE
The sensitivity of the downstream device must also meet the condition below:
sensitivity (In) x 2 ≤ fault current (Ief).
≥ 2 current discrimination OK
Ikmin
Partial discrimination
When the sensitivity discrimination condition is not met, discrimination is said to be partial.
However if the breaking-time discrimination condition is not met, there is no discrimination between
the two residual-current protective devices (even if the sensitivity discrimination condition is met).
Cascading
Default and individual parameter settings
On the Project parameters tab, in the zone for device selection, it is possible to request that the
system attempt to set up cascading for all final protection devices, i.e. those immediately upstream of
the loads. It is on the final circuits that there is the greatest number of outgoers and consequently that
cascading can provide the greatest benefits.
In addition, there is an individual parameter for each circuit breaker in the installation, among the
circuit-breaker properties, to activate or deactivate system attempts to establish cascading.
Limits on cascading
Certain configurations in electrical installations making cascading impossible:
the circuit breaker selected for cascading is supplied by two parallel circuits,
the circuit breaker selected for cascading and the upstream circuit breaker are on opposite
sides of a LV/LV transformer.
No cascading
No cascading
No search for a
cascading solution
If withdrawability is not required, Ecodial proposes solutions without taking the feature into account.
In the results zone, Ecodial indicates whether a withdrawable version exists for each device.
Drawout Masterpact NT circuit Withdrawable Compact NSX Plug-in Compact NSX circuit
breaker (on a chassis). circuit breaker (on a chassis). breaker (on a base).
If the option is not required, Ecodial proposes solutions without taking the option into account.
In the results zone, Ecodial indicates whether the option exists for each device.
If the option is not requested, Ecodial selects only devices that cannot be remotely opened.
In the absence of an indication (parameter set to Any), Ecodial proposes solutions without taking the
option into account.
In all cases, Ecodial indicates in the results zone whether each device can be remotely opened or not.
Visible break
For certain applications, visible breaking of circuit may be required for safety reasons.
On a device offering visible break, the operator can see via a transparent screen that the contacts are
in fact open. For example, the Interpact INV range offers a double safety function with visible break
and positive contact indication.
If visible break is required on a switch, Ecodial selects only switches offering the function.
If it is not required, Ecodial selects only devices not offering the function.
In the absence of an indication (parameter set to Any), Ecodial proposes solutions without taking the
function into account.
In all cases, Ecodial indicates for each device in the results zone whether the function is available.
Type A
Tripping is ensured for residual sinusoidal alternating currents and specified residual pulsating direct
currents.
Type B
Tripping is ensured for currents identical to those for class A and for residual direct currents produced
by three-phase rectification.
In addition, Schneider Electric offers the following types of residual-current devices in its catalogue:
SI (super immunised) with reinforced immunity to nuisance tripping in polluted networks,
SiE designed for environments with severe operating conditions.
The table below presents the recommended type and immunity level as a function of the external
conditions and the level of disturbances on the electrical network.
Masterpact circuit breaker equipped with Vigicompact NSX iC60 circuit Type M and P
a Micrologic 7.0 control unit circuit breaker breaker with Vigirex relays
add-on Vigi
module
Procedure if the cumulative voltage drop for a load exceeds the permissible
value
If the calculated, cumulative voltage drop exceeds the maximum, permissible value, Ecodial displays a
message to signal the error.
To clear the error, reduce the voltage-drop tolerances for the upstream circuits supplying the load (
Circuit voltage-drop tolerances).
In the example below, the calculated voltage Below, the voltage-drop tolerance for cable WD3
drop for load AA7 is 6.06%, i.e. greater than the has been reduced to 3%. Ecodial consequently
maximum permissible value of 6%. The increases the size of the cable and the voltage
tolerance for circuit voltage drops is set to 5%. drop for load AA7 is now less than 6% (4.98%).
u
+3.86% u tolerance
5% 3%
u
+ 1.93%
To maintain the maximum voltage drop for AA7 to less than 6%, it is necessary to reduce the voltage
drops on the upstream circuits (WD3 and WD7) by reducing the voltage-drop tolerance(s).
There are two possible methods.
Reduce the tolerances for all upstream circuits, in which case the size (cross-sectional area)
of all upstream circuits will be increased.
Reduce the tolerance for a single upstream circuit, namely the circuit selected by the designer
as the best for an increase in size.
Many devices in a wide range of fields include this type of circuit. They are the main causes of H3
harmonics.
Field Devices
Residential TV, hi-fi, video, microwave ovens, compact fluorescent lamps (CFL), etc.
Services Microcomputers, printers, photocopiers, fax machines, CFLs, etc.
Industry Switch-mode power supplies, variable-speed drives, CFLs, etc.
THDI ≤ 15% 15% < THDI ≤ 33% 33% < THDI ≤ 45% THDI > 45%
Sneutral = Sphase/2 is Sneutral = Sphase Sphase = Sneutral Sphase = Sneutral
permissible (1) Sphase is decisive Sneutral is decisive Sneutral is decisive
Neutral protected Factor = 0.86 IBneutral = 3 X THDi x IBphase IBneutral = 3 X THDi x IBphase
Factor = 0.86 Factor = 1
Alternate selection
Alternate solutions may be accessed only after a calculation has been validated. If that is the case and
the Select another product command is launched, the selection window automatically opens the
Calculated products window. Then simply select the desired solution using the values proposed in
the selection zone. The results zone is updated with the new solution. When OK is clicked, the
solution is confirmed (locked), i.e. it will be used for future calculations.
Manual selection
A prior, validated calculation is not required to access solutions in the catalogue. If a calculation has
not yet been validated, the selection window automatically opens the Entire catalogue window. If a
calculation has been validated, Ecodial opens the Calculated products selection window. Select
Entire catalogue to access the entire catalogue.
When a product is selected manually from the catalogue, it is "locked" for use in future calculations.
Ecodial includes a function to waiver thermal protection for circuit breakers supplying loads.
In this case, two types of circuit breakers are proposed by Ecodial:
circuit breakers without thermal protection and equipped with an MA trip unit,
circuit breakers equipped with a control unit enabling inhibition of thermal protection (e.g.
Micrologic 5.0).
In compliance with the recommendation contained in NF C 15-100, Ecodial sizes the circuit breaker
and the cable to accept 1.5 times the design current of the circuit.
Depending on the type of system earthing, there are a number of dependencies between the different
short-circuit currents (Ik3max, Ik1min, Ief, Ief2min) that must be entered.
Ecodial checks the consistency between the parameters ( Consistency of LV-source input
parameters).
These equations are also valid for the impedance of the PEN conductor in the TN-C system (with a
distributed neutral).
Depending on the type of system earthing, there are a number of dependencies between the different
short-circuit currents (Ik3max, Ik1min, Ief, Ief2min) that must be entered.
Ecodial checks the consistency between the parameters ( Consistency of LV-source input
parameters).
U U
cmin r cmax r
ZPE
3
-
3
Ief Ik3max
U U
cmin r cmax r
R PE 3- 3 PF
Ief Ik3max
sc
XPE ZPE 2 RPE 2
Depending on the type of system earthing, there are a number of dependencies between the different
short-circuit currents (Ik3max, Ik1min, Ief, Ief2min) that must be entered.
Ecodial checks the consistency between the parameters ( Consistency of LV-source input
parameters).
U U
cmin r cmax r
3 3
ZPE -
2 Ief2min Ik3max
U U
cmin r cmax r
3 3
RPE - PFsc
2 Ief2min Ik3max
XPE ZPE 2 RPE 2
Depending on the type of system earthing, there are a number of dependencies between the different
short-circuit currents (Ik3max, Ik1min, Ief, Ief2min) that must be entered.
Ecodial checks the consistency between the parameters ( Consistency of LV-source input
parameters).