Checking sensors
(cont.)
Viessmann Pt500A (green ID label)
860
780
700
620
540
460
-20
20
60
Temperature in °C
Fig. 54
Checking MCB/fuses
Fan
MCB/fuse location: See page 22.
Heat pump control unit
Fuse location: See from page 28.
■
Fuse F1 is located on the mains terminal of the heat
pump control unit.
■
Fuse F3 is located on the main PCB.
Fuses F1 and F3:
6.3 A (slow), 250 V~
■
■
Max. power loss
2.5 W
≤
Danger
Removing the fuse does not switch the power
circuit to zero volt. Contact with 'live' compo-
nents can lead to serious injury from electric cur-
rent.
Before working on the equipment, always
ensure that the power circuit is also at zero
volt.
100
140
180
The 6.3 AH (slow) MCB/fuse is located at the mains
terminals of the fan.
Maintenance
67