Summary of the content on the page No. 1
Gas–fired boiler
LGB
Control Supplement
Flame Guardian WMBC-1A
RM7895C Controller Electronic Pilot System
IRI
Contents
I. Installation ..................... 2
II. Gas piping ...................... 5
III. Wiring ............................. 5
IV.Startup ......................... 10
V. Sequence of operation 11
VI.Parts list ....................... 12
Indicates presence of hazards that can cause severe personal injury, death or
substantial property damage.
Indicates special instructions on install
Summary of the content on the page No. 2
LGB (Series 2) — Control Supplement I Installation 1. For use with LGB-6 through 12 boilers. 2. LOCAL INSPECTOR MUST CERTIFY BOILER FOR IRI COMPLIANCE. 3. Assemble pilot burner and flame sensor to main burners with pilot brackets. See Figures 2 and 3. Install ground wiring as shown in Figures 2 and 3. 4. Reinstall burner assemblies. See Table 1 for pilot burner and flame sensor locations. 5. Assemble control panel to boiler. See Figure 1. 6. Install gas controls as shown in Figure 4, page 4.
Summary of the content on the page No. 3
Flame Guardian WMBC-1A Electronic Pilot System – IRI I Installation – continued Sensor 10-32 x 5/16“ Q179 Pilot Figure 2 Machine Screws(2) Burner Igniter Q179 pilot burner assembly Locating Slot Ground Leadwire: Connect to WMBC Panel Terminal G2 (Ground Terminal) Pilot Mounting Bracket Burner Support Bar 10-32 x 1/4“ Pilot Line Tubing Machine Screws (2) Sensor Lead Main Burner (with Pilot Mounting Compression Bracket) Igniter Lead LGB-A56 Union 6-32 x 5/16“ Type ”F” Figure 3 Self Tapping Screws(
Summary of the content on the page No. 4
LGB (Series 2) — Control Supplement I Installation – continued Figure 4 IRI gas train schematic 3 5 7 6 Boiler Jacket 18 12 2 18 4 17 9 11 10 1 8 13 14 15 16 GAS PIPING DIAGRAM - LGB (Series 2) IRI Gas Train 1 Manual main shut-off gas valve 10 Manual leak checking gas valve 2 Low gas pressure switch 11 Regulating diaphragm gas valve (two stage) 3 Pilot manual shut-off valve 12 High gas pressure switch 4 Motorized gas valve w/ on/off actuator 13 Main flame sensor 5 14 Pilot gas pressure regulator
Summary of the content on the page No. 5
Flame Guardian WMBC-1A Electronic Pilot System – IRI II Gas piping 1. Size gas piping considering: a. Diameter and length of gas supply piping. b. Number of fittings. c. Maximum gas consumption (including any possible future expansion). d. Allowable pressure drop from gas meter outlet to boiler. For pressure drops, see ANSI-Z223.1 – latest edition. 2. Size natural gas piping from table below. Size piping to provide proper inlet pressure to gas valve when operating at rated input. a. Inlet gas
Summary of the content on the page No. 6
LGB (Series 2) — Control Supplement Flame Guardian WMBC-1A Electronic Pilot System – IRI Figure 5 — WMBC-1A panel wiring schematic 6 Part Number 550-141-807/0298 Part Number 550-141-807/0298 7
Summary of the content on the page No. 7
LGB (Series 2) — Control Supplement Figure 6 — WMBC-1A panel wiring diagram – factory wiring 8 Part Number 550-141-807/0298
Summary of the content on the page No. 8
Flame Guardian WMBC-1A Electronic Pilot System – IRI Figure 7 — WMBC-1A field wiring diagram Part Number 550-141-807/0298 9
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LGB (Series 2) — Control Supplement IV Start-up Turn off electrical power supply and gas supply to boiler before making the following connections and adjustment. Failure to do so can cause severe personal injury, death or substantial property damage. 1. Disable high fire by disconnecting the blue wire in the two-stage gas valve. 2. Connect manometer to gas manifold (manometer must be capable of measuring 0” to 14” W.C.). 3. Turn on electrical power supply and gas supply to boiler. 4. Fire boile
Summary of the content on the page No. 10
Flame Guardian WMBC-1A Electronic Pilot System – IRI V Sequence of operation 1. Operating control begins startup sequence: a. Limit control contacts are closed. b. Purge timer is energized. 2. Flame safeguard control pilot circuit energizes after 2.0 seconds. a. Pilot gas valve opens. b. Ignition transformer energizes. c. Yellow “pilot on” lamp lights. d. Pilot ignition spark begins. e. Pilot ignites. f. Pilot flame proves. 3. Flame safeguard control energizes main flame circuit: a. Blue “gas va
Summary of the content on the page No. 11
LGB (Series 2) — Control Supplement VI Parts list – Table 3 Description Size Vendor/Part Number Weil-McLain Part Number Primary Control Honeywell RM7895C1012 510-350-431 Prepurge Timing Card 2.0 Seconds Honeywell ST7800A1005 510-350-432 Flame Amplifier Honeywell R7847A1033 510-350-434 Electric Bulb 120V Sylv. 120MB/CHI Min. CM8-967 * Fuse 6 Amp. Bussman MTH-6 * Relay 120V DPDT Honeywell R4222D1013 510-311-012* Control Timer SSAC EDRM427 510-350-430 Gas Cock, ¼ M x ¼ F Conbraco 53-300-01 * Pilot
