Electrical System Description - Quincy QSF Series Instruction Manual

Section II – Description
Never assume it is safe to work on the unit because it is not operating. It
may be in the automatic stand-by mode and may restart at any time.
Follow all safety instructions in the "Preparing for Maintenance" or
"Service" chapters.

Electrical System Description

A diagram of the electrical system is shown in the parts manual sent with the compressor. A wiring
diagram is also included in the control panel on all Quincy QSF compressors.
NOTE:
Due to continuing product improvements and updates, it is suggested that the wiring diagram
included in the control panel be used when servicing the electrical control.
NOTE:
Standard drive motors are open drip proof 1800 RPM with a maximum ambient temperature rating
0
of 104 F. They are not suitable for salt laden, corrosive, dirty, wet or explosive environments.
The QSF series compressors utilize 460V incoming power through a magnetic motor starter. A
transformer in the control panel reduces this voltage to 120 VAC for the various controls on the unit,
which is then reduced to 24 volt for the electronic controls. These controls include the pressure
transducer, high air temperature switch and probe, solenoid valve and the various indicator lights. Other
incoming line voltages are available as options. The compressor is provided with a NEMA 1 enclosure.
Optional panels include NEMA 4.
Air-cooled models utilize a second magnetic starter for the fluid cooler fan motor. If the fan motor
starter overload trips out for any reason, the compressor unit will shut down.
High voltage could cause death or serious injury. Disconnect all power
supplies before opening the electrical enclosure or servicing.
Safety Sensors
Two high air temperature (HAT) sensors are standard on the QSF units. These sensors protect the unit
by sensing unusually high temperatures and shutting the unit down. One is located in the discharge line
from the compressor. The second sensor is located at the minimum pressure check valve. These non-
adjustable sensors are set to trip at approximately 225
8
! WARNING !
! WARNING !
0
F.
Quincy Compressor – QSF Series