Ariston NIMBUS PLUS M NET Manual page 73

WARNING:
Make ground connection prior to any other electrical connections.
The internal and external units must be powered separately.
To prevent any risk, the power supply cable of the outdoor and indoor unit must only be replaced by the technicians of the
after-sales service.
External Unit electrical connection
• When removing the front panel, the electric parts appear at the front side.
• The power supply cables can be inserted into the precut holes (A) in the back (Take off the knockout part)
• Be sure to fix the power cable (B) and indoor/outdoor communication cable with all the clips provided into the units and if
necessary add bundling bands sold on the market in order to be sure that they will not be in contact with the compressor and
the hot pipes.
• To ensure good tensile strength, the electric cables must be fastened using the cable-holder on the plate (C).
• Connect the communication cable to the terminals as identified by their respective numbers on the terminal block of indoor
and outdoor unit.
According to the installation instructions, all devices for disconnection from the power supply mains must have a contact
opening (4 mm) to allow total disconnection according to the condition provided for the overvoltage class III.
ATTENTION
If the installation involves the use of thermostats or chrono-thermostats for managing the heat demand, it is necessary to ensure
that they do not have a proportional band control logic. In fact, this logic could cause an inefficient behavior of the system and
not guarantee the satisfaction of the room temperature set-point. The use of modulating thermostats or modulating chrono-
thermostats or ON / OFF thermostats without proportional band logic is recommended.
Warning: Before obtaining access to terminals, all supply circuits must be disconnected.
External unit terminal block 1Ph
EH1 EH1 ST1 ST1 L N
L N
EH1 - Antifreeze electric heaters for water piping.
ST1 - Safety thermostat connection (230 V) for under-floor system (shunt connection).
B
C
External unit terminal block 3Ph
EH1 EH1 ST1 ST1 L1 L2 L3 N
L
A
Bus terminal block
B T
N
BUS
73 / GB