Patterson-Kelley THERMIFIC MODU-FIRE, Supplement Manual

Page: 12 / 27

Modu-Fire
®
Gas-Fired Boiler Installation/Operation
Configuration Level:
The configuration level is used to set up the control
for the sensors used, and the functioning of the
alarm relay. The configuration level must be
adjusted by a qualified factory authorized personnel
only.
3.12.1B Remote/Local Switch
The firing rate of the boiler is controlled by an
external analog signal, usually from a multiple
boiler control. The boiler turns on and off as
directed by the external control.
An operating limit control ensures that the boiler
temperature does not exceed the set value.
Remote/Local and Firing Rate Switches
Local control of the boiler can be obtained by
placing the Remote/Local switch in the local
position. With the boiler in local mode, the
up/down switch can be used to control the firing rate
of the boiler. Pressing this switch in the up
direction increases the firing rate. Placing this
switch in the down position decreases the firing rate.
Local control is used for setting up and testing the
boiler.
3.12.2 Air Flow Adjustments
The air flow is pre-set at the factory prior to
shipment. The air (and gas ) may have to be
adjusted for local conditions. All air flow
adjustments must be performed by qualified service
personnel.
The air and gas are adjusted at two firing rates: High
fire and Low fire. The boiler modulates between
these two rates to maintain a steady outlet
temperature.
Fuel adjustments for proper fuel input are made first
at High fire; then Low fire fuel adjustments are
made at Low fire.
Red
Blue
Remote/Local Firing Rate
The air flow rates are adjusted by setting the end
switches in the damper actuator. The red end switch
sets the High fire position. The blue end switch sets
the Low fire position. To set the position of the
switch, rotate the colored wheel corresponding to
either High fire or Low fire until it indicates the
desired setting. Once the desired setting is set,
move the damper to a mid position and then back to
either low or High fire as desired.
The red air flow cam should be set so that the
plenum pressure at High fire is at or below that
indicated on the rating plate for High fire. The blue
cam should be set so that the plenum pressure at
Low fire is at or above that indicated on the rating
plate for Low fire.
The air plenum pressure at Low fire must be at least
0.3” W.C.
3.12.3 Gas Pressure Adjustment
See rating plate for the minimum and maximum gas
pressure of the boiler. Each boiler is furnished with
two plugged taps in the gas manifold for test gauge
connections. One tap is located at the main gas
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