Weil-McLain LGB-4 Boiler User Manual


 
Part Number 550-141-918/0304
LGBLGB
LGBLGB
LGB
-4 -4
-4 -4
-4 &
5 5
5 5
5
Control Supplement
UCS
Nat. Gas
5
Figure 2 Wiring diagram
Sequence of
operation
1. Operating control begins start-up sequence.
a. Limit control contacts are closed.
2. Ignition control module energized.
a. Pilot gas valve opens.
b. Pilot ignition spark begins.
c. Pilot ignites.
d. Pilot proves.
e. Main gas valve opens.
f. Main burners ignite.
3. Boiler shuts down when operating control
satisfied.
For your safety, turn off power supply before making
electrical connections to avoid possible electrical shock
hazard.
On failure to sense pilot flame, control will wait 5
minutes then retry for ignition.
"Hot" side of line voltage to boiler must be wired
directly to limit circuit, then fed to transformer
primary.
All wiring must be installed according to requirements
of the National Electrical Code and any national, state
or local code requirements having jurisdiction. All
wiring external to boiler jacket must be N.E.C. Class 1.
The boiler must be electrically grounded according to
the National Electrical Code, ANSI/NFPA No. 70 latest
edition. Use 105
o
C thermoplastic wire, or equivalent, if
any original wire must be replaced. GND (burner)
lead wires must be 125
o
C wire.
Canadian installations must conform to CSA C22.1
Canadian Electrical Code Part 1 and any local or
provincial codes.
Wiring to boiler must be No. 14 gauge or heavier.
Install in conduit.
A separate electrical circuit with a fused disconnect
switch (15 amp. recommended) should be used for the
boiler.
Determine right or left electrical supply wiring.
Attach electrical junction box to inside jacket end
panel. Screws and nuts are provided.
Attach control transformer to junction box.
Complete wiring per wiring diagram, Figure 2,
pages 4 and 5.
Install ignition control ground connection as
shown in Figure 1 and wiring diagram, Figure 2.
In Canada — attach chain between junction box
and transformer with S-hooks.
Wiring
procedure
Wiring
requirements
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation resulting in servere personal
injury, death or substantial property damage.