Installation•
21
3110086 EHC20 UK 110515
M.1.2 Housing top
Terminal box cover
Cover screw
M.2
Electrical connection
Before working on the device, disconnect the power supply and ensure that the device cannot
be switched on again! Check that the power is switched off.
The electrical connection work should only be carried out by a specialist in accordance with the
regulations in place. The controller must not be used if there is visible damage to the housing,
e.g. cracks.
Extra low voltage leads such as temperature sensor leads should be kept away from the mains
cables. Temperature sensor leads should only be inserted into the left-hand side and mains
cables only into the right-hand side of the device.
An omnipolar cut-off device, e.g. an emergency heating switch, should be fitted to the power
supply system for the controller by the customer.
No more than 55 mm of the sheath on the leads that are to be connected to the device should
be stripped, and the sheath should reach just beyond the strain relief clamp where the cable
enters the housing.
The controller and VFS sensor must have the same ground potential. The VFS sensor has a
functional earthing system (PELV). The controller’s PE terminal must be connected to the pipe
system close to the sensor.
