MGE UPS Systems EPS 8000 - Manual (Page 13)

Introduction page 1 — 3
Users Manual
1.4 Specifications, Circuit Breakers and Powerflow Diagrams
1.4.1 Circuit Breakers
EPS 8000 UPS circuit breakers (except the battery disconnect circuit breaker QF1) are located behind the doors of
the Input/Output cabinet. Following is a brief description of the available circuit breakers and contacts, and their
function (Figures 1-2, 1-3, and 1-4).
Q1 Input isolation circuit breaker, used to isolate the UPS from the main AC input (mains 1) and provide
input current protection.
QF1 Battery disconnect circuit breaker, external to the UPS, used to disconnect the battery from the UPS.
QF1 provides isolation and protection between the UPS and its battery system.
Q3BP (optional) Maintenance bypass circuit breaker, used to supply the attached load via the bypass source
while the UPS is being serviced.
Q5N Optional UPS isolation circuit breaker, used to isolate the UPS module from the attached load.
Q4S Bypass input circuit breaker; it is used to isolate the UPS from the bypass input (mains 2) source and
provide back-feed protection. This circuit breaker is mounted inside the Input/Output cabinet for 625
and 555 kVA units.
Figure 1-2: Circuit Breaker Locations on the EPS 8000. (Q4S not shown)
I N P U T
C B, Q 1