Carrier 42GW Operation of the thermo-electric valve, Water connection, Electrical wiring

42 GW

Motorized valve and control

Automatic operation position

Thermo-electric valve head

Valve body

004 - 008 - 010 012 - 016 - 020

Operation of the thermo-electric valve

•This 3-way valve is an ON-OFF type with a very slow stroke. It is not a modulating valve so it has no PTC.

This valve is driven, as a sensible element, by the ambient thermostat of the “cassette” unit.

•The thermo-electric valve is normally closed towards the coil and open towards the bypass.

When the room temperature does not satisfy the thermostat, an electric heater activates the heating of a thermostatic element which causes the down-stroke of the piston; the valve opens after about 3 minutes about to allow water to circulate in the coil.

•If the room temperature satisfies the thermostat or if the electric power has been switched off, the valve is closed after about 3 minutes towards the coil and is opened towards the bypass.

•If an emergency occurs, the valve may be manually opened, removing the electric head, unscrewing the ring nut.

When the emergency ends, remember to reset the valve to automatic operation, repositioning the electric head; failure to do this can result in condensate formation due the water pipes, even if the unit is switched off.

Instructions for field supplied valves

Water connection

•Install valves following manufacturer's instructions; refer to the relevant figures for connection to the unit.

•Carefully insulate pipes, valve assemblies and coil connections (cold water side) to avoid condensation forming on the pipes and dripping on the false ceiling.

Electrical wiring

•Connect the room control following instructions for the control used.

WARNING:

Pass cables through the control panel cable-conduit.

•Connect valves as per the following instructions, using the wiring diagram in this chapter.

•Valves, closing the unit water inlet when there is no power supply, must be used.

ON-OFF valves (230V)

•In this case the cold water valve must be controlled by the ON- OFF signal from terminal 1 of TB3 and the hot water valve from terminal 2 of TB3.

ON-OFF valves with other voltages than 230V

•If a room control listed in the accessories table is used, follow the instructions in the previous paragraph and install two 230V relay at TB3 terminals 1, 2, 4 and 5 which will control the valve opening.

230V valve connection or

230V valve relay connection

C

H

HHeating valve or heating valve relay C Cooling valve or cooling valve relay

•If a low voltage control is used or if the control is not listed in the accessories table, the connections must be made on the unit terminal board.

Control connection

Fan speed

H = high speed

M= medium speed L = low speed

Heat Cool

GB - 10