Control cabinet type 11-21-31-41 Roof


Control cabinet 11 is intended for max. 3 x 2300W three-phase heating-cable applications
Control cabinet 21 is intended for max. 6 x 2300W
Control cabinet 31 is intended for max. 9 x 2300W
Control cabinet 41 is intended for max. 12 x 2300W

This control cabinet is intended for the thermostat-controlled frost protection of gutters and downpipes.

This cabinet may be designed to special order for loads exceeding 10A per phase.


1  main switch, three-pole
1 control switch, manual-0-automatic
1 ETF 1442 thermostat (double thermostat for gutters) including two sensors
1/2/3/4 contactor(s), 4 x 20A
1/2/3/4 ELCB(s), four-pole, 25/0,03A
1/2/3/4 operating status indicator(s) for three phases
3/6/9/12 circuit-breakers, plus control 6A
1 enclosure, Class IP54

This control cabinet is intended for wall mounting and cable entry is via top and bottom.

Putting into service:

  • Adjust the ETF 1442 thermostat adjusting knobs. Initial setting should be: Low -2 °C / High +2 °C.
  • Put the ELCB toggle switch in the ON position.
  • Turn the main switch to the ON position.
  • When the current has been switched on, the sensor LEDs light up indicating status, as explained below.

ETF 1442 Roof thermostat

Yellow LED light on: temperature is above preset operating temperature.
Green LED light on: temperature below preset operating temperature.
Red LED light on: thermostat operating.

The thermostat operates on the basis of the plus/minus system using two sensors: the “Low” sensor, in conduit, is located on the roof and will detect any “thawing temperature” on the roof, that is to say, if the temperature exceeds the preset “Low” value.

At the same time, the “High” sensor, located on a wall facing north, will sense any air temperature falling below the preset “High” value and causing ice to be formed in gutters and downpipes.


If, in certain weather conditions, icicles or surface ice should form, then the thermostat knobs may be adjusted in the following way:

  • Check the thermostat LEDs.
  • If the green light is on: turn the ”Low” adjustment knob clockwise towards a lower temperature, until the red LED lights up.
  • If the yellow light is on: turn the ”High” adjustment knob anti-clockwise towards a higher temperature.
  • For lowest possible operating costs, the knobs should be adjusted so as to be as close as possible to zero!

Connecting up

Connection of the cabinet is made to a 5-conductor system.

The 5 x 1,5 mm² supply cable (maximum 5 x 4mm²) is connected to the main switch of the cabinet and to the neutral and earth terminal blocks.

The heating coils are connected directly to the cabinet’s earth terminal block (G-G), to the neutral terminal block (terminal block 1), and to the outgoing phases L1 (terminal block 2), L2 (terminal block 3) and L3 (terminal block 4). The sensor lead (integral, 3m) may be jointed up to a length of 50m without affecting temperature adjustment knob accuracy.