20 Wiring Considerations
8.1 Power Wiring
1. Power wiring must be run in individual, separ ate conduits or cable trays. Refer to the Outline
and Terminal Details drawings (Figure 8 to Figure 15 and Figure 29 to Figure 32)for
locations of the various power connectionsw ithinthe UPS and S CC. In particular,note the
location of the rectifierinput power connections.
2. Observe local, state and national electrical codes. Verify utility po wer and its overcurrent
protection rating will acco mmodate the UPS input rating, inclu ding battery recharging.
3. A safety ground wire must be run f rom building ground to ground point in the UP S Module
Cabinets, the System Control Cabinet, and the Power-Tie Cabinet (if applicable). See S ections
7.1 through 7.4. The grounding conductor shall comply w ith the following conditions of
installation:
a. An insulated grounding conductor must be sized i n accordance with the NEC and local
codes. It must be green (with or wi thout one or more yellow stripes) and be installed as
part of the branch circuit that supplies the unit or system.
b. The grounding conductor described above is to be grounded to earth a t the service
equipment or, if supplied by a separately derivedsystem, at the s upplytransformer or
motor-generator set in accordance with the ins tructions in Section 7 of this Manual.
c. The attachment -plug receptacles in the vicinity of the unit or syste m are all to be of a
grounding type, and theg roundingconductors serving these receptacles are to be
connected to earth ground at the service equipment.
4. When possible, input to the UPS and bypass should be four wire plus ground . When input is
straight delta, the UPS artificial neutral kit should be ordere d. When input is corner-
grounded delta, the isolatedneutral kit should be ordered.
5. Observe clockwise phase rotation of all power wi ring. Phase A leads Phase B leads Phase C. A
qualified electrician should check the pha se rotation.
6. Power cables must be rated for less than 2 volts line drop at maximum rat ed system current.
7. If site equipment includes a backup generator and autom atic transfer switch(es), consult the
manufacturers of those devices for information on sizing an d interfacing to the UPS system.
8. The installing contractor can remove the a ccess plates from the left and right side of the c able-
access area in the top of the UPS in order to cut entry holes for conduit. For units that also
have bottom cable access, there is a th ird access plate on the right side of the module.
CAUTION
Power and control w iring must be separated!
CAUTION
Aftercutting holes in the access plates,be certain that no foreign matter (metal
shavings, sawdust, i nsulation or wire fragm ents, etc.) remains inside t he UPS.
Likewise be certain to block any “e xtra” holes in the plates through which
foreign matter couldlater enter the UPS.