Emerson 3000/ITR Manuel D’Utilisation

The control system is divided into four separate circuits. The control voltage circuits are individually 

protected by fuses located on the transformer/fuse board. If any of the fuses are blown, first eliminate 

shorts, then use spare fuses supplied with unit. Use only type and size of fuse specified for your unit.
The small isolation transformer on the board supplies 24 volts to the main control board. The trans-

former is internally protected. If the internal protector opens, the transformer/fuse board must be 

replaced. Also check the control voltage fuse on the main control board before replacing the trans-

former/fuse board.

The Fan Safety Switch is located in the low voltage compartment and consists of a diaphragm switch 

and interconnecting tubing to the blower scroll. The Fan Safety switch is wired directly to the control 

circuit to activate the alarm system if the airflow is interrupted

The optional high-temp sensor is a bimetal-operated sensing device with a normally closed switch. 

This device will shut down the entire unit when the inlet air temperature exceeds a preset point. It is 

connected between Terminals 1 and 2 at Plug P39.

The optional smoke detector power supply is located on the base of the upflow units, and at the top of 

downflow units. It is constantly sampling return air through a tube. No adjustments are required.

The optional water detection devices available are a point leak detection sensor and a zone leak detec-

tion kit.

The point leak detection sensor provides leak detection at a critical point. A simple two-wire connec-

tion signals the alarms at a Liebert environmental unit or at a monitoring panel. Run wires to the 

Liebert unit and connect them to terminals 24 and 51, 55 or 56. Use NEC Class 2, 24V wiring. The 

sensor contains a solid state switch that closes when water is detected by the twin sensor probes. The 

sensor is hermetically sealed in all thread PVC nipple and is to be mounted where water problems 

may occur. The sensor should be located 6-8 feet (2-2.5m) from the environmental control unit in a 

wet trap or near a floor drain. It should not be mounted directly under the unit.

Risk of fire or explosion. Can cause injury or death.
Do not use near flammable liquids or for flammable liquid detection.