Page 31
©
2013 Magnum Energy, Inc
.
Operation
NEUTRAL IN
AC GROUNDS
Power Transformer
FET Bridge
AC
DC
DC POSITIVE
DC NEGATIVE
AC
Output
Relay
NEUTRAL OUT
AC2 Hot
Transfer Relay
HOT OUT
GEN IN (AC2)
GRID IN (AC1)
GRID
OUT
CB1
(60A)
AC1 Hot
Transfer Relay
120
VAC
GRID
IN
120
VAC
DC
OUT
CB2
(60A)
CB3
(60A)
3.2 Standby
Mode
The MSH-RE Series features an internal battery charger and an automatic transfer relay when
operating in Standby mode. The Standby mode begins whenever AC power (utility grid or generator)
is connected to the inverter’s AC input. Once the AC voltage and frequency of the incoming AC
power is within the AC input limits, an automatic AC transfer relay is activated. This transfer
relay passes the incoming AC power through the inverter to power the AC loads on the inverter’s
output. This incoming power is also used to activate a powerful internal battery charger to keep
the battery bank charged in case of a power failure. Refer to Figures 3-2 (GRID) and 3-3 (GEN)
to see the
fl
ow of power from the AC input to the DC and AC output while in Standby mode.
NEUTRAL IN
AC GROUNDS
Power Transformer
FET Bridge
AC
DC
DC POSITIVE
DC NEGATIVE
AC
Output
Relay
NEUTRAL OUT
AC2 Hot
Transfer Relay
HOT OUT
GEN IN (AC2)
GRID IN (AC1)
GEN
OUT
CB1
(60A)
AC1 Hot
Transfer Relay
120
VAC
GEN
IN
120
VAC
DC
OUT
CB2
(60A)
CB3
(60A)
Figure 3-2, Power Flow – Standby Mode (GRID Input)
Figure 3-3, Power Flow – Standby Mode (GEN Input)
