Thermal Product Solutions Environmental Test Chamber Watlow 942

Ensure the LN2 supply pressure is between 20 to 25 PSIG

Is the chamber at the extreme cold temperature limit?

Is the LN2 completely evaporating?

Readjust the valve if necessary

Ensure no liquid nitrogen contacts the door gasket

Disconnect all power to the chamber before starting maintenance

Inspect and clean the conditioner fans / blower wheels and condenser fans (air-cooled units). Ensure they spin freely and are tight on their shafts.

Clean the evaporator coil in the chamber conditioning plenum.

Inspect inside the machinery compartment for loose electrical connections, frayed wires, loose components, or other potential problems.

Inspect the electric heaters inside the chamber conditioning plenum for sagging elements, broken insulators, or other defects.

High Setpoint: Dial a temperature well below actual workspace temperature. Verify the instrument transfers to alarm state, disabling protected circuits.

Disconnect power supply cord and plug from the power supply receptacle.

Open the closest main power disconnect switch if chamber is hard wired.

Lockout / Tagout all electrical power to the chamber.

Push in the RTD sensor probe towards the wall of the chamber, leaving ½” to ¾” sticking out.

Conditioner Plenum Cover Removal

Remove the conditioner plenum cover by removing the four mounting screws, avoiding contact with the fan blade or RTD probe.

Air-Cooled Refrigeration System Maintenance

Inspect the condenser coil for dust or dirt accumulation.

Water-Cooled Refrigeration System Maintenance

Check the condenser water supply pressure.

Is the water flow to the open drain unrestricted?

Inspect the chamber door gasket for wear.

Does the door seal tightly around its perimeter?