RTRD

General: The RTRD transformer-based controllers inside robust, plastic casing are designed for controlling voltage-controllable three-phase fans by altering the supply voltage in five fixed steps.

Protection: An integral motor protection device is included. When thermal contacts of the fan connected to terminlas TK, protection device will cut supply voltage to the fan if the thermal contact in the fan motor is activated. The protection is reset by turning the knob to “0” for 10 seconds, after which the unit restarts.

Installation: The device is designed for vertical installation (cable inlet down) in a location where it will not be disturbed, but at the same time can be easily accessed.

Control: The steps are adjusted manually, using the control knob on the front of the unit. The indicator lamp on the front shows that the transformer is in operation.
Input terminals RT for room thermostat (or for similar functional relay) cut supply voltage to the fan when the circuit is broken. RT terminals are linked before delivery and should be linked when is not in use.
RTRD also supplied with frost protection function. Frost protection thermostat should be connected to FS terminals. When the frost protection thermostat FS breaks the circuit, RTRD will cut supply voltage to the fan. The reset performed in the same way as when the TK is triggered. FS terminals are linked before delivery and should be linked when is not in use.

Additional features: The transformer has output 230V terminals for operating dampers, electric heater batteries or other external equipment. These terminals have no current when the transformer knob is in position 0, or when the TK, FS or RT input is open.