Chapter 7 Troubleshooting 87
87
Cooling Troubleshooting
Temperature Lock Cannot be Achieved or Maintained.
Possible causes for not being able to achieve or maintain lock could include:
Ambient temperature greater than +23°C. This condition affects TE-cooled
cameras. If ambient is greater than +23°C, you will need to cool the camera
environment or raise the set temperature.
Airflow through the camera and/or circulator is obstructed. The camera needs to
have approximately two (2) inches (50 mm) clearance around the vented covers.
If there is an enclosure involved, the enclosure needs to have unrestricted flow to
an open environment. The camera vents its heat out the vents near the nose. The
air intake is near the rear of the camera.
A hose is kinked. Unkink the hose.
Coolant level is low. Add coolant. See “CoolCUBE
II
: Low Coolant (Air in Hoses)”
on page 86.
There may be air in the hoses. Add coolant. See “CoolCUBE
II
: Low Coolant
(Air in Hoses)” on page 86.
Circulator pump is not working. If you do not hear the pump running when the
CoolCUBE
II
is powered on, turn off the circulator and contact Customer Support.
The circulator is higher than the camera. Reposition the circulator so that it is 6
inches (150 mm) or more below the camera. The vertical distance should not exceed
10 feet (3 m). Typically, the camera is at table height and the circulator is on the
floor.
The camera vacuum has deteriorated and needs to be refreshed. Contact
Customer Support.
The target array temperature is not appropriate for your particular camera and CCD
array.
For a TE-cooled camera, the camera's internal temperature may be too high, such as
might occur if the operating environment is particularly warm or if you are
attempting to operate at a temperature colder than the specified limit. TE-cooled
cameras are equipped with a thermal-protection switch that shuts the cooler circuits
down if the internal temperature exceeds a preset limit. Typically, camera operation
is restored automatically in about ten minutes. Although the thermo-protection
switch will protect the camera, you are nevertheless advised to power down and
correct the operating conditions that caused the thermal-overload to occur.
Camera loses Temperature Lock
The internal temperature of the camera is too high. This might occur if the operating
environment is particularly warm or if you are trying to operate at a temperature colder than
the specified limit. If this happens, an internal thermal overload switch will disable the
cooler circuits to protect them. Typically, camera operation is restored in about ten minutes.
Although the thermal overload switch will protect the camera, users are advised to power
down and correct the operating conditions that caused the thermal overload to occur.