Danfoss Commercial Compressor Crankcase Heater User Manual

Important Information from the Manual

This document provides installation and safety instructions for Danfoss Commercial Compressor Crankcase Heaters. These heaters are designed to prevent refrigerant migration during off-cycle periods. Note that these heaters are not self-regulating; they require an external control system to energize the heater when the compressor is switched off.

Installation

Installation must be performed by qualified personnel in compliance with all safety procedures. Follow these steps for proper mounting:

• Install the heater at the lower part of the compressor, below the sight glass, where oil accumulates.
• Ensure the heater is in good contact with the compressor surface along its entire length.
• Lock the clip and tighten the mounting screw. The maximum torque is 2 Nm.
• Do not cut the lead wires of the heating belts, as they are made of glass fiber.

Electrical Connection

• Ensure the main power supply is switched off and isolated before performing any electrical connections.
• A separate, permanent electrical supply is recommended for the heater.
• Verify that the power supply voltage matches the characteristics specified on the heater cable.

Start-up and Operation

• Perform an insulation test before the initial start-up.
• Check the resistance values according to the model table provided in the manual.
• Ensure the minimum oil superheat required by the specific compressor model is respected.

Operating Conditions and Maintenance

The heater is designed for an operating temperature range of -40°C to 105°C. Note: If the ambient temperature is below -5°C and the wind speed is above 5 m/s, it is recommended to thermally insulate the heater to limit energy losses.