UPS WITH BYPASS ELECTRICAL INSTALLATION

See Table 2 for recommended conductor sizes to wire the input circuit breakers.

Table 2. Recommended Wire Sizes

Input Circuit Breaker Size

75°C Copper Wire Size

Conductor Screw Torque

 

 

 

25A

5.3 mm2 (10 AWG)

4.0 Nm (35 lb in)

40A

8.4 mm2 (8 AWG)

4.5 Nm (40 lb in)

60A

21.2 mm2 (4 AWG)

5.1 Nm (45 lb in)

80A

26.7 mm2 (3 AWG)

6.6 Nm (50 lb in)

100A

33.6 mm2 (2 AWG)

6.6 Nm (50 lb in)

125A

42.1 mm2 (1 AWG)

6.6 Nm (50 lb in)

FOR U.S. INSTALLATIONS, READ THIS IMPORTANT NOTE!

This table lists the mm2 and AWG wire size for each circuit breaker size shown on the wiring diagrams. The minimum recommended circuit breaker sizes for each model and voltage application are listed on the wiring diagrams.

Conductor sizes shall be no smaller than the 75°C wire size based on the ampacities given in Table 310–16 of the National Electrical Code, ANSI/NFPA 70-1999, and article 220. All circuit conductors, including the neutral conductor, must be the same size (ampacity) wire. Code may require a larger AWG size than shown in this table because of temperature, number of conductors in the conduit, or long service runs. Follow local code requirements.

Bypass Switches

Bypass switches are available in two types: Make-Before-Break (MBB) and Break-Before-Make (BBM).

An MBB switch makes a new connection before it breaks the original connection. For example, if you turn an MBB switch from UPS to LINE, the bypass switch connects the load to AC input power before disconnecting the load from UPS output power. (As noted in Figure 38 on page 57, MBB switches may not be used in certain system configurations.)

A BBM switch breaks the original connection before it makes a new one. If you turn a BBM switch from UPS to LINE, the switch disconnects the load from UPS output power before connecting the load to AC input power.

The bypass switch has four positions as described in Table 3.

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Eaton 9170+ UPS (3–18 kVA) User's Guide S 164201393 Rev E www.eaton.com/powerquality

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Eaton Electrical ASY0673, ASY0529 Bypass Switches, Recommended Wire Sizes, Input Circuit Breaker Size 75C Copper Wire Size