Pressure Sensors; Checking Fuses - Viessmann BW 35 .AHT PW Series Installation And Service Instructions Manual

Repairs
Checking sensors
Curve, Pt1000
1600
1500
1400
1300
1200
1100
1000
900
800
-50 0 50
Temperature in °C
Fig. 40

Pressure sensors

Pressure sensors for soldering or with threaded fittings
are used.
Sensor
Low pressure sensor
High pressure sensor
Curves
20
16
12
8
4
0
-0.5 0 0.5 1
MPa
-5 0 5 10
bar
Printing
Fig. 41
Up to 7 bar (0.7 MPa)
A
Up to 18 bar (1.8 MPa)
B
Up to 30 bar (3 MPa)
C
Up to 50 bar (5 MPa)
D

Checking fuses

Fuses in the front wiring chamber
■ Power circuit fuse, compressor 1 and 2 (see sepa-
rate "Connection and wiring diagram")
Subject to heat pump/compressor output; see chap-
ter "Specification"
■ Power circuit fuse, system components (see sepa-
rate "Connection and wiring diagram")
56
(cont.)
100 150
1.5 2 2.5 3
15 20 25 30
R1234ze refrigerant
Up to 9 bar (0.9 MPa)
Up to 40 bar (4 MPa)
3.5 4 4.5 5
35 40 45 50
Danger
Contact with live components can lead to seri-
ous injury from electric current.
Before working on the appliance, ensure that
the power circuit is also at zero volt.
Removing fuses does not switch the power
circuit to zero volt.