TM 9-4940-568-20
2-84
L2
L1
FU3
FU2
GND
T3
T1T2
WIRE 5
WIRE 1
X1
208VAC
INPUT
TERM 7
PRESSURE
RELIEF
SWITCH
L3
L2
L1
GND
TERMINAL
BOARD
TRANSFORMER
COMPRESSOR
OFF/ON
SWITCH
120VAC OUTPUT
X2
X1
WHITE WIRE 7
BLACK WIRE 6
TERM 6
LIMIT
SWITCH
AT
COMPRESSOR
X2
WIRE 2
WIRE 3
WIRE 6
L1 and L2 provide 208 VAC to a transformer on wires 2 and 3. The transformer drops the voltage to 120 VAC.
The hot wire sends 120 VAC to the compressor off/on switch. When the switch is closed, the voltage is sent
out to the compressor limit switches and oil level safety switch. It returns on wire 6 to terminal 6 of the
compressor terminal board. Wire 6 sends voltage to energize the 3fAC relay and sends 208 VAC to the
compressor.
Figure 2-6. Air Compressor VAC Schecmatic.
