Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 135

Checking the pressure sensors
4
3
2
1
0
0 0.1
MPa
0 1
bar
Pressure
Fig. 83
Checking the fuse
■ Fuse F1 is located in the HPMU electronics module:
See page 51.
Fuse F2 is located on the luster terminal for the heat
■
pump control unit power supply: See page 59.
Fuse type:
■ 6.3 A H (slow), 250 V~
Max. power loss 2.5 W
■ ≤
Danger
Removing fuses 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.
0.2 0.3 0.4
2 3 4
0.45
4.5
1. Switch off the power supply.
2. Open the HPMU electronics module.
3. Check the fuse. Replace if required.
Danger
Incorrect or improperly fitted fuses can lead
to an increased risk of fire.
Insert fuses without using any force. Posi-
■
tion fuses correctly.
■ Only use structurally identical types with
the same response characteristics.
Indoor unit maintenance
135