Patterson-Kelley MOD-04 Test of Low Gas Pressure Switch, Test of High Gas Pressure Switch

Modu-Fire®Gas-Fired Boiler

the main burner shuts off (the green "Heat" indicator will go out). The high-limit switch must be manu- ally reset after testing. This same check should also be made for the "Operating Temperature" control. After completion of these tests, readjust thermostats to desired operating temperature and set high-limit temperature, typically 20º F above operating tem- perature.

3.11.4 Test of Low Gas Pressure Switch

Manual Reset

Gas Pressure Switch

The boiler is furnished with a low gas pressure switch. The operation of this switch must be checked by slowly closing the main gas cock while the burner is operating. The switch should shut down the main burner. When the gas pressure switch opens, the "Gas Press." indicator will light. Upon reopening the main gas cock, the "Gas Press." indicator should remain on until the low gas pres- sure switch is manually reset.

3.11.5 Test of High Gas Pressure Switch

The correct setting of the high gas pressure switch is essential for proper operation of the boiler. This switch is set by the factory at 4.0” w.c. and must not be changed.

This switch must be checked by factory-trained per- sonnel.

Installation

3.12INITIAL ADJUSTMENTS

3.12.1A – Configuring the Local Controller

(Applies to models furnished with programmable temperature control.)

Operating Modes:

Internal Setpoint

Night Setback (Alternate Setpoint) Outdoor Air Reset

Analog Input Setpoint (See Section 3.12.1B.)

Analog Input Direct Drive (Multiple boiler Controls)

Definitions:
SP1- Setpoint 1:	This is the primary
SP2- Setpoint 2 :	setpoint of the boiler.
	An alternate setpoint.
	Available through the
	alternate setpoint con-
	tact closure.

dSP- Differential Setpoint : ..An alternate setpoint

	differential from SP1.
	Available through the
	alternate setpoint con-
tA- Air temperature:	tact closure.
	Measurement of out-
SP.E- External Setpoint:	side air temperature.
	Measurement of the
HyS1:	external setpoint.
	Low temperature dif-
HyS3:	ferential.
	High temperature dif-
	ferential.

Internal Setpoint

The boiler water outlet temperature is controlled to SP1 (setpoint 1) and the boiler modulates to main- tain SP1 subject to the upper and lower temperature differentials and the upper and lower setpoint limit.

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