Thermo Electron 3751, Инструкция по установке и обслуживанию

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13
TROUBLESHOOTING
Problems encountered with any constant
temperature chamber will most frequently be
related to temperature control. Before proceeding
with detailed troubleshooting, be certain that the
Low Limit and High Limit controls are adjusted
properly. If the limit controls are set too close or
beyond the operating temperature, the incubator
may be consistently going into alarm. This will
result in erratic temperature control. First, the
symptoms and possible causes will be listed for
quick reference. Later, the remedies will be
suggested.
WARNING
HAZARDOUS HIGH VOLTAGE CONDITIONS EXIST
INSIDE THE CONTROL PANEL. UNPLUG LINE
CORD AND TURN "OFF" LINE SWITCH BEFORE
REMOVING THE COVER. ONLY QUALIFIED
ELECTRICAL INSTRUMENT PERSONNEL ARE
AUTHORIZED TO PERFORM TROUBLESHOOTING
AND/OR SERVICING.
SYMPTOMS AND POSSIBLE CAUSES:
Freeze-up or gradual drop in chamber
temperature:
• No air circulation in chamber; inoperative fan
(see Remedy 1)
• Heater (see Remedy 2)
• Power Supply PCB Assembly (see Remedy
3)
• RTD Temperature Probe (see Remedy 3,
Step D and/or Remedy 4).
Temperature variations at set point (poor
control):
• Excessive ambient temperature variations
(see Remedy 10)
• Compressor Relay failure (see Remedy 12)
• No air circulation in chamber; inoperative fan
(see Remedy 1)
• RTD Temperature Probe Location (see
Remedy 5)
• Ice buildup on evaporator coils (see
paragraph on "Defrosting")
• RTD Temperature probe (see Remedy 3,
Step D and/or Remedy 4).
• Power Supply PCB Ass'y (see Remedy 3)
Adjusting the Intake and Exhaust Ports
The exhaust port is the top port on the door. Open
it slightly by turning it counterclockwise to permit
exhausting of chamber air. The intake port is the
bottom port on the door. Open the intake port by
turning it counterclockwise to permit an air
exchange in the chamber.
SERVICING
WARNING
SERVICE SHOULD BE PERFORMED BY QUALIFIED
SERVICE PERSONNEL. EXERCISE CARE AS LINE
VOLTAGE IS PRESENT IN THE CONTROL
COMPARTMENT.
If it is ascertained, after review of the
Troubleshooting Section, that refrigeration service
is needed, contact the White-Westinghouse
Service Organization.
In any communication with White-Westinghouse
or Precision, include the model and serial numbers
from both nameplates located near the bottom of
the door opening. Specific reference must be made
to White-Westinghouse Policy Procedure Letter
82-2605, which covers the service requirements
for this particular model.
For assistance in locating the nearest White-
Westinghouse authorized service or parts supplier,
contact:
White-Westinghouse
P.O. Box 7181
Dublin, OH 43017
1(800) 245-0600