Electrical hookup
Installation manual – System controller
27
3
3.7
TEMPERATURE PROBES CONNECTION TO K18 UNIT
Figure 3�11
Collector temperature probes connection to K18 unit
A
Detail of K18 unit terminal block
GHP NTC 10k Beta 3977 probe (included with K18 unit)
GHP' NTC 10k Beta 3977 probe (available as OSND004
optional)
Use of temperature sensors
GHP always
GHP'
K18 Simplygas
models: only if an auxiliary boiler is
present and DHW service is made by K18
models
K18 Hybrigas
: pre-installed in the machine;
connect as shown in the figure if the DHW service man-
aged by the K18 unit is present
Use shielded cable
2 x 0.5 mm
2
up to 40 m
2 x 0.75 mm
2
up to 60 m
2 x 1.0 mm
2
up to 80 m
2 x 1.5 mm
2
up to 120 m
Connect the shield to a ground terminal on the K18 unit's
terminal block.
3.8
AUXILIARY BOILER CONNECTION (IF PRESENT) TO THE K18 UNIT (ONLY FOR K18
SIMPLYGAS MODELS)
Figure 3�12
ON/OFF request connection, optional 0-10 V output (temperature setpoint) and optional alarm signal for the auxiliary boiler on the
unit terminal block
A
K18 unit terminal block detail
B
Auxiliary boiler
C
ON/OFF contact request (2x0.75 mm
2
cable)
D
0-10V input for setpoint acquisition (*)
E
Alarm signalling output (mandatory SELV voltage-free
contact) (*)
(*) (optional); shielded cable 2x0.75 mm²
ON/OFF
AUX
BOILER
+10
0
+ AL
0 AL
AUX BOILER
A
D
E
C
B
