DPM-2 SETUP
Common Terminology
Reset Ratio:
The ratio between supply water temperature
and outdoor temperature� For example, a ratio of 1�0 or
1:1 means, for every one degree the outdoor temperature
decreases, there will be a one degree increase in supply
water temperature�
Max. Temp:
The maximum supply water temperature when
the outdoor temperature is 0°F�
Differential:
Measurement used to determine when the
boiler will turn on and off. A ten degree differential will turn
the boiler on at five degrees below the control point and
off at five degrees above while a twenty degree differential
will turn the boiler on at ten degrees above and off at ten
below. The effect of differential is to prevent quick cycling of
the boiler�
General Wiring Notice
All primary wiring must be 14 AWG minimum. Torque
terminal screws 6 to 7 inch pounds.
U.S.A. -
National Electric Code and any other nation-
al, state, or local code requirements. Wiring must be
N.E.C. Class 1.
CANADA -
C.S.A. C22.1 Canadian Electrical Code
Part 1 and any other national, provincial, or local
code requirements. Wiring must be C.S.A. C22.1
C.E.C. Part 1.
INSTALLATION MANUAL AND OPERATING INSTRUCTIONS
Electrical Specifications & Wiring
WARNING
Electrical shock hazard� Disconnect power before
installing or servicing� Failure to follow these
instructions could result in death or serious injury�
!
DPM-2 Control Set-up
1.
Determine the reset ratio and adjust “Reset Ratio Trim
Pot.” If heat curve is unknown, try ratio of 1.0.
2.
Turn “Max. Temp. Trim Pot” to design temperature of
supply water (water temperature needed when outdoor
temperature is 0°F)�
IMPORTANT:
Boiler high limit must be set higher than
“Max. Temp.” setting
plus
“Differential” or unit may operate
erratically�
3.
Set “Differential Trim Pot” to scale (10°F). Boiler will
turn off when water is 5°F above control point and
back on again when water is 5°F below control point�
If boiler does “Quick Cycle,” increase trim pot. Optimal
performance is obtained when this setting is as low as
possible, but still allows for a reasonable cycle time�
6
PN 240005132 Rev. D [11/15/2021]
