Backfeed Protection
 DANGER |
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Hazard of electric shock, explosion, or arc flash
In systems where backfeed protection is not a part of
the standard design, an automatic isolation device (such as a breaker,
switch, or contactor with trip function, meeting the requirements
of IEC62040-1 or UL1778 5th edition – depending on which standard
apply to your local area), is required to be installed to prevent
hazardous voltage or energy at the input terminals of the isolation
device. The device must be rated and controlled according to the specifications
in this manual.
Failure to follow these instructions will result in death or serious injury.
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When the UPS input is connected through external isolators that, when opened, isolate the neutral or when the automatic backfeed isolation is provided external to the equipment or is connected to an IT power distribution system, a label must be fitted at the UPS input terminals, and on all primary power isolators installed remote from the UPS area and on external access points between such isolators and the UPS, by the user, displaying the following text (or equivalent in a language which is acceptable in the country in which the UPS system is installed):
| DANGER |
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Hazard of electric shock, explosion, or arc flash
Risk of Voltage Backfeed. Before working on this circuit:
Isolate the UPS and check for hazardous voltage between all terminals
including the protective earth.
Failure to follow these instructions will result in death or serious injury.
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An additional external isolation device must be installed in the UPS system. A magnetic contactor or a disconnect device with shunt trip functionality can be used for this purpose.
The isolation device must be able to withstand the electrical characteristics as described in Specifications.
Single Mains with Backfeed Box
Dual Mains with Backfeed Box
