Auxiliary Low Gas Pressure Switch - Viessmann Vitocrossal 200 CM2 500 Service Instructions Manual

Burner Service

Auxiliary Low Gas Pressure Switch

Legend
1 Low gas pressure switch cable
Legend
A DIN rail (junction box)
B Auxiliary low gas pressure switch or external shut-off (dry contact)
34
Vitocrossal 200, CM2 400, 500 and 620 Service
Installation steps
1. Disconnect boiler power supply.
2. If the boiler has already been installed, shut off main
gas supply to the boiler and disconnect gas supply
piping.
3. Supply and install gas piping components as required
(see illustration).
4. Route cable beneath the top rail 1 as shown.
Secure using plug-in cable retainers as shown.
5. Make electrical connections as shown below.
6. Set the low gas pressure switch to 4.5" wc.
7. Open gas supply to the burner.
Note: The setting must be higher then the GW1
pressure switch (4" w.c.) located on the gas
valve. If a 4" w.c. setting is required then the
GW1 pressure switch must be set below 4"w.c.
8. Using an approved gas leak detector, check gas line
and low gas pressure switch.
9. Reconnect power to the boiler.
Note: External vent line is not required. If necessary the
d" NPT vent opening on the Honeywell low
gas pressure switch can be used.
CM2 Boiler Low pressure gas
connection switch connection
G
26 (L) COM
27 (L)
Wire color
Green

White
NO Black