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1-6
1.3 ELECTRICAL SPECIFICATIONS
a. Evaporator Blower Motor
Evaporator Motor
Brushless
Bearing Lubrication
Factory Lubri-
cated (addi-
tional grease
not required)
Horsepower
0.6
Full Load Amps (FLA)
20
Operating Speed (RPM)
2200
Voltage
27-vdc
Dropping Resistor
0.6-ohms
300-watts
b. Condenser Fan Motor
Condenser Motor
Brushless
Bearing Lubrication
Factory Lubri-
cated (addi-
tional grease
not required)
Horsepower
0.6
Full Load Amps (FLA)
19
Operating Speed (RPM)
1800
Voltage
27-vdc
Dropping Resistor
0.25-ohms
300-watts
1.4 SAFETY DEVICES
Safety devices protect system components from
damage caused by unsafe operating conditions.
If the High Pressure Switch (HPS) or Low Pressure
Switch (LPS) opens due to unsafe operating conditions,
the A/C operation will automatically stop. The A/C stop
light will illuminate to indicate an unsafe condition has
occurred. The evaporator blower motors will continue to
run to circulate air throughout the bus.
During any mode of operation (A/C, Vent or Heat),
the evaporator or condenser motors will stop if excessive
current draw is sensed by the circuit breakers. All circuit
breakers, when opened, must be manually reset by
depressing the breaker button.
When the High Pressure Switch (HPS) or Low
Pressure Switch (LPS) opens and unit operation stops,
place the driver’s A/C switch to the OFF position and
back to the ON position to reset the A/C Stop Relay and
de-energize the stop light.
Table 1-3. Safety Devices
Unsafe Condition
Safety Device
Device Setting
1. Excessive current draw by the
Circuit Breaker --- CB1
Opens at 15 amps
boost pump motor.
Manual Reset
2. Excessive current draw by
Circuit Breaker --- CB2
Opens at 40 amps
evaporator blower motor no. 2.
Manual Reset
3. Excessive current draw by
Circuit Breaker --- CB3
Opens at 40 amps
evaporator blower motor no.1.
Manual Reset
4. Excessive current draw by clutch.
Circuit Breaker --- CB6
Opens at 10 amps
Manual Reset
5. Excessive current draw by
Circuit Breaker --- CB7
Opens at 40 amps
condenser motor no.1.
Manual Reset
6. Excessive current draw by
Circuit Breaker --- CB8
Opens at 40 amps
condenser motor no. 2.
Manual Reset
7. Excessive current draw by
Circuit Breaker --- CB9
Opens at 40 amps
condenser motor no. 3.
Manual Reset
8. High system pressure.
High Pressure Switch (HPS)
Opens at 425
10 psig
Automatic reset
(30
0
.7 kg/cm
@
)
9. Low system pressure
Low Pressure Switch (LPS)
Opens at 10
3 psig
Automatic Reset
(0.70
0
.21 kg/cm
@
)