3 gas heat module – Reznor MAPS II Unit Installation Manual User Manual

Page 42

Form I-MAPS II, Page 42

FIGURE 34 - Signal

Conditioner,

P/N 134170, used in

Option AG57, Gas

Controls with 6:1

Turndown

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FIGURE 33B - Gas Train for Heat Section Sizes 100-400 with

Optional 6:1 Turndown (Option AG57, natural gas only) and

both optional Low and High Gas Pressure Switches

Single-

Stage Valve

controlling

flow to

1/3 Burner

Single-Stage Valve

controlling flow to

Full (Non-Split) Burner

To 2/3

Burner

Section

To 1/3

Burner

Section

Two orifices to

to Full Burner

Single-

Stage Valve

controlling

flow to

2/3 Burner

STAGE 1

STAGE 2

STAGE 3

FIGURE 35A - Gas Train for Heat

Section Sizes 450-700 with 3:1

Turndown (Option AG55)

Sequence of Operation:

The 1/3 burner valve and the 2/3

burner valve are energized. After

20 seconds the 1/3 burner valve is

de-energized (this is Stage 1).

For Stage 2, the full (non-split)

burner valve and the 1/3 burner

valve are energized, while the 2/3

burner valve is de-energized.

Stage 3 brings the 2/3 burner valve

back on so all valves are energized.

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FIGURE 35B - Gas Train for

Heat Section Sizes 450-700

with Optional 6:1 Turndown

(Option AG57, natural gas

only)

NOTE: See FIGURE 34

for signal conditioner.

9.3.2 Gas Heat Module - Mechanical (cont'd)

9.3.2.1 Gas Piping and Pressures (cont'd)

9.3 Gas Heat

Module

9. Optional Equipment including Heat Sections (cont'd)