Operating Instructions - RBI LCD Series Installation & Operation Manual

Lcd series finned copper gas boilers & water heaters

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Installation & operation manual (48 pages)

Table Of Contents

Table of Contents

Page 26

Ignition Trial:

1. Blower delay timer TD1 times out and the flame

sense module, FSM, is energized.

2. The FSM starts the 10-second ignition trial,

energizing relay R7, the pilot solenoid valve and the

spark generator.

3. The pilot valve and spark generator are energized

for the 10-second ignition trial. When the pilot flame

is sensed, the FSM sends 24VAC to its MV terminal

energizing the safety and low fire-side of the main

solenoid valves and relay R8, de-energizing R7 and

the spark generator.

4. If the pilot flame isn't sensed, the FSM de-energizes

the PV terminal and waits 5 minutes before initiating

the second ignition trial. The blower(s), pump(s) and

optional power venter will remain on during this time.

5. On CSD-1 equipped units the blower(s) and optional

power venter will shut down and the boiler/water

heater will lock if the second ignition trial fails. The

unit must then be manually reset by depressing the

reset button on the left jacket panel.

6. On non-CSD-1 equipped units the FSM will wait 10

minutes after the second unsuccessful ignition

attempt then begin the ignition process described

in step 3 above. The FSM will continue to cycle the

unit through steps 3, 4 and 6 until the unit lights or

the demand for heat is removed.

Main Burner

Once the pilot is proven, the FSM sends 24VAC to its

MV terminal energizing the safety and low-fire side of

the main solenoid valves.

Normal Operation

• Staging is controlled by the return water aquastat.

Relays R2 and R2R are energized by the return water

aquastat when more heat input is required. The

hi-speed windings of the blower(s) are energized.

• Relay R9 is energized when the hi-fire pressure switch

senses adequate air pressure to sustain hi-fire

combustion. R9 energizes the hi-fire side of the pilot

and main solenoid valves.

• Stage 1 will operate first and last.

NOTE: For a change from stage 1 to 2, a 7 second

LCD time delay is provided in the pressure switch

switching circuit (PD6). The time delay provides a

hold state that allows the blower to reach full speed

and close the high fire pressure switch before it is

energized to confirm proper air flow.

LCD INSTALLATION AND OPERATION INSTRUCTIONS

Demand Satisfied:

1. When the demand for heat is satisfied the operator

switch will open, de-energizing relays R2, R2R, R8,

R9, TD1, TD3, TD4, the FSM and the pilot, main

and safety solenoid valves. The pilot and main

flames are extinguished.

2. The blower delay timer TD3 starts the 80 second

post-purge timing. The blower(s) shut(s) off when

TD3 times out.

3. The pump delay timer TD4 starts the post-purge

timing. The pump(s) remain on for 0.1 to 10 minutes

then shut(s) off when TD4 times out.

High Limit, Low Water Flow, Low Gas Pressure, High

Gas Pressure, Power Venter Interlock Faults

1. Electrical power to the gas valves, blower(s) and

power venter will be interrupted if any safety is

tripped.

2. The manual reset high limit can be reset by

depressing the rubber plug in the front top jacket

panel.

Low Air (Blocked Flue/Air Inlet)

• The pressure switches will monitor blower airflow.

• Air monitoring will begin at pre-purge. If a low air

condition is present, power will not be supplied to the

FSM. The blower(s) will remain on.