Temperature Sensors, Type Pt500A - Viessmann Vitocal 300-G Pro Series Installation And Service Instructions For Contractors

Repairs
Checking sensors

Temperature sensors, type Pt500A

600
580
560
540
520
500
480
460
440
420
400
-40 -30 -20 -10
Outside temperature in °C
Fig. 43
Checking MCBs/fuses
For fuses in the front wiring chamber, see page 33 and
page 32.
■ Power circuit MCB/fuse, compressor 1 and 2 (see
separate connection and wiring diagram):
Subject to heat pump/compressor output, see chap-
ter "Specification".
■ For power circuit fuse for system components, see
separate "Connection and wiring diagram".
■ For control circuit fuse, see separate connection and
wiring diagram.
1. Switch OFF the power supply.
2. Opening the wiring chamber.
3. Check fuses. Replace if necessary.
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 specified response characteristics.
66
(cont.)
0 10 20 30 40
For the fuse in the upper wiring chamber, see page 39.
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.