42 G8000 Series Installation and Operation Manual

11.4 External Breakers

The G8000 UPS units are not equipped with circuit breakers. Qualied personnel should provide the
external breakers for the AC input/output, bypass input and DC input.
See Figure 11.1 – External Wiring Diagram, for the circuit position of the breakers.
Table 11.7 shows the G8000 UPS minimum external breaker rating for each capacity. The Bypass, AC
Input, and AC Output require 3-pole breakers.
TABLE 11.7 UPS MINIMUM DEVICE RATINGS
CapaCity Rated
Output

input BReakeR

Rating

Output BReakeR

Rating
dC input

BReakeR Rating

80 kVA 480 V/277 V 480 V – 150 A 480 V – 125 A 500 VDC – 300A
100 kVA 480 V/277 V 480 V – 200 A 480 V – 150 A 500 VDC – 350A
125 kVA 480 V/277 V 480 V – 200 A 480 V – 200 A 500 VDC – 400A
150 kVA 480 V/277 V 480 V – 300 A 480 V – 250 A 500 VDC – 600A
225 kVA 480 V/277 V 480 V – 400 A 480 V – 350 A 500 VDC – 900A
300 kVA 480 V/277 V 480 V – 600 A 480 V – 500 A 500 VDC – 1200A
500 kVA 480 V/277 V 480 V – 800 A 480 V – 800 A 600 VDC – 1200A

11.5 Grounding Wire

WARNING
Be sure to ground the UPS as specied.
Using the UPS without a proper ground will deteriorate the insulation,
cause leakage of currents and electric shock.The resistance to ground
should be less than or equal to 10 ohms.
The 80/100/150/225kVA earth grounding bus’ are located inside, at the bottom-front of the unit.
The 300 kVA earth grounding bus is located inside, at the top-left of the unit.
The 500 kVA earth grounding bus is located inside, at the bottom front of the units.
Use a AWG 2 (or 38 mm2) or larger cable for the grounding wire. Run the grounding wire through the
opening at the bottom, or through a hole in the top conduit landing plate (if available). See Figure 11.12.
Connect either the top or bottom earth ground bus, but not both, to the grounding wire.
The ground wire must have a crimp terminal with a 1/2 in. (12 mm) diameter bolt hole. The ground bus has
33/64 in. (13 mm) bolt hole. The connect the crimp terminal and ground bus together using a 7/16 in. (10
mm) diameter bolt.