IV Wiring – continued
Sequence of operation 1. Operating control begins
a. Limit control contacts are closed.
2.
On failure to sense pilot flame or main flame, control will wait 5 minutes then retry for ignition.
a.Pilot solenoid opens.
b.Pilot ignition spark begins.
c.Pilot ignites.
d.Pilot proves.
3.Main
a.Secondary gas valve opens.
b.Main gas valve opens to low fire position.
c.Main burners ignite at low fire.
d.Main flame sensor proves low fire carryover.
e.Main gas valve opens to high fire position.
f.Main burners increase to high fire.
4.Dual base assembly
5.Boiler shuts down when the operating control is satisfied.
Wiring Procedure 1. Determine right or left electrical supply wiring.
2.Attach electrical junction box(es) to inside jacket end panel. Screws and nuts are provided. For dual base boilers, use offset nipples (provided) to connect juction boxes together, then hang junction boxes by screwing top box to boiler jacket. See Figure 4.
3.Attach control transformer(s) to junction box(es).
4.Drill 1/8” hole in interior jacket panel midway between ignition control panel and left jacket panel. Mount wire support clip using sheet metal screw (furnished).
5.Complete wiring per wiring diagram, Figure 3, pages 6 and 7. Terminate at secondary gas valve in valve junction box with wirenuts and strain relief provided.
“Hot” side of line voltage to boiler must be wired directly to limit circuit, then fed to transformer primary(ies). Dual Base: “R” terminal of secondaries are to supply power to bases independently of each other. Do not wire “R” terminals together.
6.Install pilot proving and main flame proving ground connections as shown in Figures 1, 2 and 3. Route wires through wire support clip.
7.Canada only - attach chain between junction box(es) and transformer with
Figure 4
Junction box assembly dual base boilers
8 | Part Number |
