Helmer Scientific i.Series
®
Ultra-Low Freezer
Service and Maintenance Manual
360173-A/C
7
Additional Sensors
Additional temperature sensors may be installed through one of the ports on the rear wall of the cabinet. The ports are located in the
top-left corner and bottom-left corner. The ports consist of two plastic caps - one inside the cabinet and one on the outside. The cabinet
insulation fills the void between the plugs.
NOTICE
Do not drill holes in the cabinet. Drilling holes may damage the insulation in models equipped with vacuum-insulated panels, or
may damage the evaporator coil causing a loss of refrigerant.
Notes
• Use a tool with a diameter only large enough to accommodate the sensor wiring.
• Helmer recommends installing additional sensors through the upper or lower rear ports provided.
•
The rear ports may also be used to install tubing for an optional (field-installed) CO
2
/ LN
2
back-up refrigeration system.
Install Additional Sensor
1. Remove the plastic plugs on the outside and inside of the cabinet.
2. Use a screwdriver or similar tool to pierce the insulating foam.
3. Insert the tool from the outside, through the foam, to the inside of the cabinet.
4. Secure the sensor inside the cabinet as necessary.
5. Seal the hole in the foam using Permagum putty or press-in cork tape, ensuring a tight seal.
Chart Recorder (optional)
If installed, refer to the Temperature Chart Recorder Operation and Service Manual.
The temperature chart recorder has a back-up battery system, enabling a period of continuous operation if power is lost. Battery life
varies by manufacturer as well as voltage level remaining. Providing full power is available, back-up power for the chart recorder is
available for up to 14 hours.
Prior to use:
Calibrate chart recorder to match chamber temperature
Setup and Operation
Access chart recorder by pressing and releasing the door.
