Blocked Vent Shutoff Switch - Weil-McLain WTGO 4 Series Manual

WTGO
OIL-FIRED NATURAL DRAFT WATER BOILER — SERIES 4 —
Connect wiring — blocked vent shutoff switch option

Blocked vent shutoff switch

Canada, blocked vent shutoff switch kit
(see parts list page 36) must be installed.
See Figure 21.
When using the OVD damper kit, the
BVSS is required, and is integrated into
the damper harness wiring.
When using the BVSS without the OVD
damper, the BVSS is wired directly to the
Combination limit control as follows.
The wiring diagram in Figure 22 shows
boiler wiring only up to the burner
disconnect. For additional information,
refer to manufacturer's instructions.
Electric shock hazard – Turn off electrical
power supply at service entrance panel
before making any electrical connections
to avoid possible electric shock hazard.
Failure to do so can cause severe personal
injury or death.
Figure 21
Blocked vent shutoff switch installation
Part number 550-142-332/0421
SERVICE TECHNICIAN ONLY — read and follow completely.
After installing BVSS switch, proceed as follows
1. Disconnect power.
2. Install Shutoff Switch (BVSS) Wiring Harness (P/N 591-391-942, which
is included in BVSS kit P/N 591-624-650) as follows:
a. Remove cover from BVSS Box.
b. Install straight fitting end of the harness on the BVSS Box. Install
elbow (90º) end fitting on the right side of the Hydrolevel control.
c. Install both the fork ends to the screw terminals on the BVSS Switch
as per the wiring diagram, (see Figure 22).
d. Replace BVSS box cover.
e. Locate Combination Control, remove cover, and disconnect red
wire from "B1" terminal.
f. If red wire from Step "e" has uninsulated female end, replace it
with insulated female end as supplied in kit.
g. Connect female end of Shutoff Switch BVSS Harness (blue wire)
to "B1" terminal.
h. Connect male end of Shutoff Switch BVSS Harness to the red wire
removed in Step "e".
i. Replace Combination Control Cover.
3. Turn on power and verify safe operation of the appliance.
4. Restore boiler to normal operation.
Figure 22
Boiler Manual
BVSS wiring diagram
120 vac
field wiring
Low voltage
field wiring
120 vac
factory wiring
Low voltage
factory wiring
27