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Modu-Fire
®
Gas-Fired Boiler Installation
20
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 ad-
justed by factory-trained personnel only.
3.12.1B Optional Remote Control
This option is used when 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 is used for setting up and testing the
boiler. Local control of the boiler firing rate can be
obtained by placing the Remote/Local switch in the
local position (This does not bypass # 1 start inter-
lock, # 1 start interlock must be made for the boiler
to fire). 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 in-
creases the firing rate. Placing this switch in the
down position decreases the firing rate.
To operate the boiler independently from the BMS
(Building Management System) or sequencer, an
external bypass switch of the BMS must be installed
by the control contractor.
WARNING!
Do not bypass any safety limits with this switch.
3.12.2 Air Flow Adjustments
The air flow is pre-set at the factory prior to ship-
ment. The air (and gas) may have to be adjusted for
local conditions. All air flow adjustments must be
performed by factory-trained 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 tempera-
ture.
Fuel adjustments for proper fuel/air ratio are made
first at High fire, then at Low fire.
Air Flow Adjustments
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 de-
sired 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 cabi-
net 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 cabinet pressure at Low fire
is at or above that indicated on the rating plate for
Low fire.
The cabinet air pressure at Low fire must be at least
0.3” w.c.
Firing Rate
Remote/
Local
Red Blue