Recommended Cable Sizes for IEC
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hazard of electric shock, explosion, or arc flash
Failure to follow these instructions will result in death or serious injury.
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The maximum number of cable connections per busbar:
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4 on input/output/bypass busbars
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4 x 240 mm2 on input/output/bypass busbars
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4 x 240 mm2 or 8 x 150 mm2 on DC+/DC- busbars
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8 on N busbar
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16 on PE busbar
Cable sizes in this manual are based on the minimum requirements in table B.52.3 and table B.52.5 of IEC 60364-5-52 with the following assertions*:
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90 °C conductors
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An ambient temperature of 30 °C
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Use of copper or aluminum conductors
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Installation method F
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Single layer on a perforated cable tray
PE cable size is based on table 54.2 of IEC 60364-4-54.
If the ambient temperature is greater than 30 °C, larger conductors are to be selected in accordance with the correction factors of the IEC.
Copper
Copper
UPS rating | 400 kW | 450 kW | 500 kW | |||||||||
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Voltage (V) | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 |
Input phases (mm2) | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 185 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 |
Input PE (mm2) | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 240 | 1 x 240 | 1 x 185 | 1 x 150 | 1 x 240 | 1 x 240 | 1 x 240 | 1 x 240 |
Bypass/output phases (mm2) | 2 x 120 | 1 x 240 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 120 | 1 x 240 | 2 x 185 | 2 x 150 | 2 x 150 | 2 x 150 |
Bypass PE/output PE (mm2) | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 150 | 1 x 150 | 1 x 120 | 1 x 120 | 1 x 185 | 1 x 150 | 1 x 150 | 1 x 150 |
Neutral (mm2) | 2 x 120 | 1 x 240 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 120 | 1 x 240 | 2 x 185 | 2 x 150 | 2 x 150 | 2 x 150 |
DC+/DC- (mm2) | 2 x 240 | 3 x 150 | 3 x 185 | |||||||||
DC PE (mm2) | 1 x 240 | 2 x 120 | 2 x 150 | |||||||||
Inverter midpoint cable for 3-wire parallel (mm2) | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 185 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 |
Aluminum
UPS rating | 200 kW | 250 kW | 300 kW | 350 kW | ||||||||||||
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Voltage (V) | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 |
Input phases (mm2) | 1 x 185 | 1 x 185 | 1 x 185 | 1 x 185 | 2 x 120 | 2 x 120 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 120 | 2 x 185 | 2 x 185 | 2 x 185 | 2 x 150 |
Input PE (mm2) | 1 x 95 | 1 x 95 | 1 x 95 | 1 x 95 | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 120 | 1 x 185 | 1 x 185 | 1 x 185 | 1 x 150 |
Bypass/output phases (mm2) | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 120 | 1 x 185 | 1 x 185 | 1 x 185 | 1 x 185 | 2 x 120 | 1 x 240 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 120 | 2 x 120 |
Bypass PE/output PE (mm2) | 1 x 95 | 1 x 95 | 1 x 95 | 1 x 70 | 1 x 95 | 1 x 95 | 1 x 95 | 1 x 95 | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 120 | 1 x 150 | 1 x 150 | 1 x 120 | 1 x 120 |
Neutral (mm2) | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 120 | 1 x 185 | 1 x 185 | 1 x 185 | 1 x 185 | 2 x 120 | 1 x 240 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 120 | 2 x 120 |
DC+/DC- (mm2) | 2 x 120 | 2 x 150 | 2 x 240 | 3 x 150 | ||||||||||||
DC PE (mm2) | 1 x 120 | 1 x 150 | 1 x 240 | 2 x 120 | ||||||||||||
Inverter midpoint cable for 3-wire parallel (mm2) | 1 x 185 | 1 x 185 | 1 x 185 | 1 x 185 | 2 x 120 | 2 x 120 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 120 | 2 x 185 | 2 x 185 | 2 x 185 | 2 x 150 |
Aluminum
UPS rating | 400 kW | 450 kW | 500 kW | |||||||||
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Voltage (V) | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 | 380 | 400 | 415 | 440 |
Input phases (mm2) | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 | (3 x 185)* | (3 x 185)* | 2 x 240 | 2 x 240 | (3 x 185)* | (3 x 185)* | (3 x 185)* | (3 x 185)* |
Input PE (mm2) | 1 x 240 | 1 x 240 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 1 x 240 | 1 x 240 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 150 |
Bypass/output phases (mm2) | 2 x 185 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 185 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 |
Bypass PE/output PE (mm2) | 1 x 185 | 1 x 150 | 1 x 150 | 1 x 150 | 1 x 240 | 1 x 240 | 1 x 185 | 1 x 150 | 1 x 240 | 1 x 240 | 1 x 240 | 1 x 240 |
Neutral (mm2) | 2 x 185 | 2 x 150 | 2 x 150 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 185 | 2 x 150 | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 |
DC+/DC- (mm2) | 3 x 185 | 3 x 240 | 4 x 185 | |||||||||
DC PE (mm2) | 2 x 150 | 2 x 185 | 2 x 185 | |||||||||
Inverter midpoint cable for 3-wire parallel (mm2) | 2 x 240 | 2 x 240 | 2 x 240 | 2 x 240 | 3 x 185 | 3 x 185 | 2 x 240 | 2 x 240 | 3 x 185 | 3 x 185 | 3 x 185 | 3 x 185 |
Guidance for Organizing Input, Bypass, And Output Cables
The input, bypass, and output cables must be grouped in circuits. On raceways, use one of the two shown cable formations.
Load Sharing in Bypass Operation in a Parallel System
The impedance of the bypass paths need to be controlled in a parallel UPS system. When operating in bypass mode, the parallel load sharing is determined by the total impedance of the bypass path comprising cables, switchgear, static bypass switch, and cable formation.
NOTICE |
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Risk of equipment damage
To ensure correct load sharing in bypass operation in a parallel system, the following
recommendations apply:
Failure to follow these instructions can result in equipment damage.
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ECOnversion Limits for Parallel UPS Systems
ECOnversion requires a minimum load percentage on the UPS for parallel UPS systems. The minimum required load percentages depend on the power cable sizes.
Standard ECOnversion Limits Based on Recommended Cable Sizes
UPS rating | Minimum load % |
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200 kW | 34% |
250 kW | 27% |
300 kW | 23% |
350 kW | 19% |
400 kW | 17% |
450 kW | 15% |
500 kW | 14% |
The other prerequisites to use this table include:
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The values are calculated based on the use of recommended cable sizes.
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Installations with maximum two cables on each phase are supported.
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The bypass and output cables must have equal length for all UPSs.
Standard ECOnversion Limits Based on Non-recommended Cable Sizes
UPS rating | Minimum load % |
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200 kW | 50% |
250 kW | 40% |
300 kW | 34% |
350 kW | 29% |
400 kW | 25% |
450 kW | 22% |
500 kW | 20% |
The other prerequisites to use this table include:
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The values are calculated based on the scenario of using non-recommended cable sizes.
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Installations with three or four cables on each phase are supported.
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The bypass and output cables must have equal length for all UPSs.
For 3-Wire Parallel Systems Only
In a parallel installation installed as a 3-wire AC configuration, the inverter midpoint of each UPS must be interconnected by cable in a daisy chain configuration. The inverter midpoint cable size can be found in the recommended cable sizes table.
When the inverter midpoint of the parallel UPSs is permanently connected, there is still potentially dangerous voltage present on the neutral busbar inside the UPS even after the UPS has been isolated from the parallel system for maintenance and has been completely shut down. Due to the dangerous voltages on the neutral busbar, all service activities that need access inside the I/O section by opening the inner door require full shutdown of the entire parallel system and transfer to maintenance bypass.
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Hazard of electric shock, explosion, or arc flash
Failure to follow these instructions will result in death or serious injury.
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