Operation - Honeywell VS8420C Installation Instructions Manual

VS8420C,M MILLIVOLT GAS VALVE
Wiring
Follow the wiring instructions furnished by the appliance
manufacturer, if available, or use the general instruc-
tions provided below. Where these instructions differ
from the appliance manufacturer, follow the appliance
manufacturer instructions. For a typical wiring diagram,
see Fig. 6.
All wiring must comply with applicable electrical codes
and ordinances.
Disconnect power supply before making wiring connec-
tions to prevent electrical shock or equipment damage.
1. Check the power supply rating on the gas valve
and make sure it matches the available supply.
Install the transformer, thermostat, and other con-
trols, as required. When the millivolt gas valve is
controlled with a millivolt thermostat, see Table 1
for the maximum wire length which can be used.
Apply gold contacts on thermostat and high limit
control and solder the connections.
2. This valve can be used only in a self-generating
system.
3. Adjust the thermostat heat anticipator to the 0.1A
at 750 mV rating stamped on the valve operator.
Table 1. Maximum Thermostat Wire Length.
Wire Gauge (AWG)
14
16
18
20
22
69-1304
APPLY WRENCH
FROM BOTTOM OF
GAS CONTROL TO
SHADED AREA
Fig. 5. Proper use of wrench on gas valve.
Double Wire Length (m)
31
20
13
8
5
ECO Connection (Supplementary)
1. Push the ECO into the window of the gas valve.
(See Fig. 5.)
2. The leadwires of the ECO must be equipped with
insulated 6.3 mm female quick connect terminals.
3. Leadwire length must not exceed the length as
shown in Table 2.
Table 2. Maximum Length (mm) of Supplementary
Limit Leadwires When Using Q309A Thermocouple.
Thermocouple
Length (mm) AWG 14 AWG 16
300 1200
500 1000
600 900
800 800
900 600
1000 500
1200 300
1500 Do not use.

OPERATION

The Millivolt Gas Valve System includes a gas valve,
quick drop-out thermocouple, thermopile, millivolt ther-
mostat and a pilot burner. In this configuration, the
thermopile drives the operator and the quick dropout
thermocouple operates the power unit. See Fig. 7.
As an option, a piezo can be mounted on the valve to
ignite the pilot burner. The piezo creates a spark when
the plunger is depressed. The connecting wires of the
piezo include a terminal to connect to the electrode of
the pilot burner. The piezo is replaceable.
4
M12679
AWG 18
800 500
700 400
600 400
500 300
400 200
300 200
200 Do not use.