Control cabinet type 11-21-31-41(22/33/44)

TYPE 11-21-31-41 (22/33/44) CONTROL CABINET: MODE OF OPERATION

Control cabinet 11 is intended for max. 3 x 2300W(three-phase) heating-cable installations
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 designed for heating-cable applications on pipes, containers and tanks, and underground and in floors and the like, all with thermostat control.

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

Components

1 main switch, three-pole
1 control switch, manual-0-automatic
1 Termonic 26090 thermostat including one sensor (cabinets 22,33,44 have one thermostat for each three-phase group)
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
4/7/11/13 circuit-breakers
1 enclosure, Class IP55

The control cabinet is intended for wall mounting and has cable entries on all sides.

Putting into service

  • Using a screwdriver, set the thermostat (Termonic) adjustment knob for the required temperature (the temperature range may have to be adjusted).
  • 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.

Termonic 26090

Red LED light on: sensor fault or temperature range incorrectly set.
Yellow LED light on: thermostat operating (sensor temperature below preset value).

Adjustments

Hysteresis (number of degrees between thermostat switching on and thermostat switching off) must be adjusted in such a way that the thermostat meets the temperature-control accuracy requirements.

It should be noted that the service life of the thermostat relay will be shorter if settings are used which produce low hysteresis in cases of fast processing.

If the thermostat and/or succeeding contactors should rattle on release, then hysteresis should be somewhat increased.

Change of temperature range in order to avoid end positions. An incorrect temperature range may lead to a sensor malfunction being indicated.

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), L3 (terminal block 4), alternatively to 5 x 1,5mm² or to 3 x 3 x 1,5mm² for further connecting to a junction box and/or junction boxes.

The sensor lead (integral, 3m) may be spliced up to a length of 50m without affecting temperature adjustment knob accuracy. The sensor is connected to terminal block 117, 118 using 2 x 1.5mm².