Gardner Denver EAQ99T Operating And Service Manual Download

Page: 37 / 78

13-21-602 Page 36

Discharge Thermistor

- This sensor is located directly in the compressor discharge. Its signal is used

to monitor compressor temperature and shut down the compressor if a coolant problem is detected.

Reservoir Thermistor

- This sensor is located near the separator and is used to monitor temperature

and shut down the compressor if high temperatures are detected.

Emergency Stop Push-Button

- This is a maintained push-button, and removes power from the

controller outputs regardless of controller status. It is located on the upper section of the panel, next to
the keypad. This should be used for emergency purposes only - use the keypad [STOP/RESET] for
normal controlled stopping.

Automatic restarting or electrical shock can cause injury or death. Open,
lockout and tagout main disconnect and any other circuits before servicing
unit.

Power Supply

- This device changes the incoming AC supply voltage to 24 volts DC for use by all unit

control devices. For 575 volt AC units only, a control transformer is provided to supply 230-240 volts AC
input to the power supply. A secondary fuse is provided on the control transformer. Refer to adjacent
labeling for replacement information.

Fuse Blocks -

Two Class CC fuse blocks provide line side protection for the power supply and control

transformer, as applicable.

Control Transformer

– This control device changes the incoming power voltage to 110-120 volts for use by

unit control devices. The transformers employed are usually connectable for several input voltages refer to
transformer label for connection prior to energizing. Two primary and one secondary fuse are provided. Refer
to adjacent labeling for replacement information.

Terminal Strip

- This provides connections for all 24 volt DC controlled devices not directly connected to

the “AirSmart” controller.

Fan Starter

- The starter is used to provide control and overload protection for the cooling fan or the

ventilation fan of water – cooled units with enclosure. Overload heaters should be selected and adjusted
based on the motor nameplate amps and the instructions located inside the cover of the electrical
enclosure. Three fuses are provided. Refer to adjacent labeling for replacement information.

Main Starter

- This starter is used to provide control and overload protection for the main drive motor.

Wiring diagrams for typical full voltage applications are illustrated on pages 45 thru 50. For Wye Delta
and less starter applications, refer to the wiring diagram included in each control box enclosure.

Overload protection is provided for each motor on full voltage and Wye Delta applications. The overloads
are adjustable and are factory set based on the motor nameplate amps and the instructions located inside
the control box door. Less starter applications utilize a control relay for control of a remote mounted
motor starter (not provided with compressor package). Wye-delta starters employ three contactors which
are controlled sequentially to provide low current starting. For wye-delta starters, the motor nameplate
amps must be first multiplied by 0.577 before using the heater table.