Install Instructions

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2. Differential (df_)
The control is factory programmed with a
Differential of 15°F. The Differential is the number
of degrees the boiler temperature must decrease
below the Operating Setpoint before the boiler can
restart. The differential is adjustable between 10°
through 30°F.
3. Circulator Overrun Time (OR_)
The control is factory programmed with a
Circulator Overrun Time of 0 minutes. Circulator
Overrun Time (also called “circulator off delay”
or “circulator post purge”) continues circulator
operation after a call for heat has ended, sending
excess heat from the boiler into the system. Ensure
system piping and zone panel settings allow water
ow to the priority zone after the call for heat ends.
The Circulator Overrun Time is adjustable between
0 through 10 minutes.
4. Circulator Pre-purge Time (PP_)
When the boiler is warm (boiler water temperature
higher than 140°F (adjustable using Start
Temperature parameter)) and there is a thermostat
call for heat, the system circulator is started and
boiler ring is delayed Circulator Pre-purge minutes.
If the temperature drops below 140°F or there is
a DHW call for heat the boiler is started without
delay. Additionally, the boiler is started without
delay if the thermostat call for heat is initiated when
the boiler water temperature is less than 140°F. This
feature helps save energy by satisfying home heating
needs with residual boiler heat rather than cycling
the boiler. The Circulator Pre-purge time has a
factory setting of 2 minutes and is eld adjustable
between 2 and 20 minutes. Refer to Table 6.
5. Start Temperature (St_)
Amount of “Heat available” is calculated by taking
the difference between measured boiler water
temperature and the Start Temperature setting.
Useful “Heat Available” is dependent on the type of
heating emitter installed in the home. Heat emitters
require a certain minimum temperature to operate
effectively. Our default settings reect cast iron
radiators. Fan Coils may require a start temperature
setting of 180°F or 160°F before providing heat
to the home. The Start Temperature has a factory
setting of 140°F and is eld adjustable between
140°F and 180°F.
6. Priority Time (Pt_)
When the Priority Time parameter is set to “on” and
Domestic Hot Water (DHW) call for heat is “on”
the DHW demand will take “Priority” over home
heating demand. During Priority Time the system
circulator will be forced “off”. Priority Time ends
and the system circulator is released to service home
heating demand when Domestic Hot Water call for
heat is over. When Priority Time parameter is set to
“Off” the DHW call for heat does not force “off” the
system circulator. The Priority Time has a factory
setting of “On” and is eld adjustable between “On”
and “Off” Refer to Table 7.
7. Domestic Hot Water (DHW) Terminal Function (dh_)
The control allows conguration of the DHW
Circulator output functionality to help the CG-D
Series integrate into each installation more
effectively. The DHW Circulator output can be
connected to a domestic hot water circulator or a
second heating zone circulator. These applications
are selected as follows:
a. When dh_ is set equal to Domestic Hot Water
Demand (h)
When there is an Indirect Water Heater (IWH)
the control provides “DHW” input terminals for
the IWH Aquastat and “DHW Circulator” output
terminals for the DHW Circulator.
When there is a DHW call for heat, the System
Circulator is “forced off”, the DHW Circulator
terminal is energized and the circulator pre-purge
time delay control logic is bypassed to allow
the boiler to re without delay. When DHW
demand ends the System Circulator “force off”
is removed, the circulator can respond normally,
and the DHW Circulator is de-energized. The
DHW call for heat is detected by a voltage on to
the "DHW" terminal. When the Priority Time
parameter is set to “off” the System Circulator
is not forced off for a DHW call for heat. Refer
to Table 7.
b. When dh_ is set equal to Second Heating Zone
(tt2)
When there is no IWH the “DHW Circulator”
output may be congured to control a second
heating zone. This is particularly helpful when
the home uses only two heating zones. The
control replaces the need for a two circulator
zone panel. When DHW Terminal Function
(dh_) is set to “tt2" the control’s two circulator
outputs are used to control two independent
heating zones. Refer to Table 8. A “TT” input
causes a call for heat and energizes the “System
Circulator” output to service heating zone 1 and
a second zone's thermostat wired to the “DHW”
input causes a call for heat and energizes heating
zone 2 circulator wired to the "DHW Circulator"
output.
When there is a Second Heating Zone (call
for heat) the boiler is started and the DHW
Circulator terminal is energized. When Second
Heating Zone terminal is de-energized the call
for heat is ended and the DHW Circulator is de-
energized. A Second Heating Zone is detected by
sensing a voltage on the DHW terminal.