Middleby Marshall PS220, PS570, PS360, PS200, PS555, PS224 PS310 manual N. Ignition Module

N. Ignition Module

1. Part Number Reference - Ignition Module

•PS360WB70 and PS360EWB ovens equipped with the Midco burner use Ignition Module P/N 31501.

•For all other oven models:

-Through 10/90 - these ovens used Ignition Module P/N 27161-0004. Some versions of this module included a separate, replaceable fuse. This mod- ule shared a common ground with the 24V trans- former and the relay coil. See Figure 73.

-11/90 or later - these ovens use Ignition Module P/N 27161-0005, included in Service Kit 42810- 0114. The module is internally grounded and the common ground with the transformer and relay coil has been eliminated. See Figure 74.

SECTION 3 - SERVICING COMPONENTS

If you are replacing the obsolete module (P/N 27161- 0004) with the current version (P/N 27161-0005), BE SURE TO DISCONNECT THE MODULE FROM THE COMMON GROUND WITH THE TRANSFORMER AND RELAY. Double-grounding of the module creates a feed- back voltage circuit that allows the module to operate without a signal from the burner/blower assembly. This procedure is explained in greater detail in the instruc- tions for Kit 42810-0114, included in the Appendices section.

2. Module Operation

The ignition module delivers 24V to the pilot ignitor when the blower motor centrifugal switch (or air pressure safety switch) is closed.

When the module detects a current flow of at least 2.0 mA through the pilot flame, it supplies 24V to the combination gas control valve, allowing the valve to operate.

Figure 73

Wiring diagram of ignition and gas valve system (obsolete ignition module 27161-0004)

Figure 74

Wiring diagram of ignition and gas valve system (current ignition module 27161-0005)

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