Transfer Switch; Derating For Altitude - Generac Power Systems Magnum MMG75D Owner's Manual

Transfer Switch

DANGER
Loss of life. Property damage. Installation must always
comply with applicable codes, standards, laws and
regulations. Failure to do so will result in death
or serious injury.
DANGER
Electrical backfeed. Use only approved switchgear to
isolate generator from the normal power source.
Failure to do so will result in death, serious injury,
and equipment damage.
WARNING
Only a trained and licensed electrician should perform
wiring and connections to unit. Failure to follow proper
installation requirements could result in death, serious
injury, and damage to equipment or property.
WARNING
Phase rotation between transfer switch and
power lines must be compatible. Incompatible
phase rotation could result in equipment
damage, death or serious injury.
Installation should be in compliance with the National
Electrical Code (NEC), state and local regulations.
Before any connections are attempted, verify the main
circuit breaker and the Control Power switch are in the
OFF (O) position and that the negative (-) battery cable
has been disconnected from the battery.
Installation of such devices must be performed by
following all directions supplied by the manufacturer of
the switch. If attaching the unit to a power supply
normally serviced by a utility company, notify the utility
company and check state and local regulations.
Familiarize yourself with all instructions and warning
labels supplied with the switch.
When the unit is used as a standby power supply, it must
be equipped with a transfer switch which isolates it from
the utility's distribution system. A transfer switch is
designed to transfer electrical loads from the normal
power source (utility) to the emergency power source
(generator) when normal voltage falls below a prescribed
level. The transfer switch automatically returns the load
back to the normal source when power is restored back
to operating levels.
Owner's Manual for Generator
(000190)
(000237)
A
B
C
(000155)
D
E
F
WHITE
(000226)
GRAY
BLACK

Derating for Altitude

All units are subject to derating for altitude; this will
reduce the available power for operating tools and
accessories connected to the receptacles. Typical
reductions in performance are 5% per 1,000 ft above
10,000 ft (3048 m) of elevation.
A
F
E
Figure 3-3. Transfer Switch Operation
Incoming Utility Power
Emergency Distribution Panel (Generator
Power)
Main Distribution Panel (Utility Power)
Transfer Switch
Power From Generator
Utility Meter
Incoming Utility Power
Normal Utility Power Circuit
Emergency Generator Power Circuit
Operation
B
C
D
17