Procedure to Operate Thermo King
Refrigerator
Prepared by Jon Brinkmann
Reviewed by Mark Klaene and French Leger
Maintained by Gretchen Van Doren
Last modified on
The proper method to operate the Thermo King refrigerator.
Cautionary Notes
Equipment Involved in
this Procedure
Procedure
CAUTIONARY
NOTES:
You must be properly trained on the use of
the refrigerator prior to accomplishing this procedure; see
training
list.
THIS OPERATION CAN BE ACCOMPLISHED BY ONE
PERSON.
THE DEW POINT AND ENCLOSURE AIR TEMPERATURES MUST
BE CLOSELY MONITORED. IF THE ENCLOSURE TEMPERATURE FALLS TO WITHIN 5 DEGREE
C OF THE DEW POINT TEMPERATURE THE REFRIGERATOR MUST BE SHUT OFF.
THE REFRIGERATOR WILL NOT TURN ON IF THE ENCLOSURE
HUMIDITY INTERLOCK DETECTS A HUMIDITY LEVEL ABOVE ITS SETPOINT, CURRENTLY 65%.
WEATHER CONDITIONS THAT GOVERN ENGAGING
THE COOLER:
operate during the day whenever the
temperature at telescope opening is expected
to be below 32 degree F, or zero degree C.
The dew point and enclosure temperatures may
be monitored with the TPM.
SAFETY WEAR: (recommended)
rubber-soled shoes
EQUIPMENT
INVOLVED IN THIS PROCEDURE
Thermo King Refrigerator;
Location: east wall of the enclosure: interior and one
exterior below the roof line; Appearance: grey.
Refrigerator control panel; Location: southeast
wall of the enclosure; Appearance: grey.
Enclosure humidity interlock; Location:
southeast wall of the enclosure; Appearance: grey.
Refrigerator timer control; Location:
southeast wall of the enclosure; Appearance: grey.
PROCEDURE:
If needed, the refrigerator should be turned on as early in the
morning as possible, preferably when the telescope is closed for the
day.
The unit is turned on at the left-most toggle switch on the
control panel. The controller takes about five seconds to run its
self-test, after which the display will show the return air
temperature.
Adjust the set point for the expected temperature at opening.
Press the button with the circular arrows in the upper right
corner of the temperature controller.
Use the up and down arrow buttons on the left to adjust the set
point.
Press the "=" button in the lower right corner to enter the set
point within five seconds.
The unit should be turned off in the afternoon before the building is opened
for ventilation.
The unit has an external timer located to the right of the control panel. It
allows the refrigerator to be run daily at predetermined times (urrently on
at 8am and off at 9am). Its manual bypass may be engaged by opening the clear
plastic cover (depress the latch on the right side of the timer) and pressing
the "enter" button once to turn the unit on, or twice to turn the
unit off. The timer is re-engaged by pressing the "run" button once.
END OF PROCEDURE