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Once initiated, Dry Fire Test can be canceled by pressing
▲up and ▼down arrow buttons simultaneously for 2
seconds. This by-pass feature is intended for installer and
should only be used when it is clear that dry condition
does not exist. Dry Fire Test is selectable in conguration
mode and can be set to Y or N. To prevent Dry Fire testing
from automatically occurring, change setting for dFt to N in
conguration mode. Do not change setting unless special
circumstances exist with application where conducting of
Dry Fire Test does not accurately detect presents of water
in the boiler.
Load Management Control (LMC)
Load management (LMC) feature can be used to
temporarily de-activate the boiler and place it in stand-by
mode. Some utility companies use this feature during peak
demand periods to load trim the utility’s power grid.
Control is equipped with auxiliary set of contacts (T
Aux) which can be used to connect a secondary heating
appliance. While the load management terminals (LMC) are
open the heating elements are prevented from energizing
and “LdC” is displayed. The call for heat on TT or DHW
terminals is then diverted to the T Aux terminals to
energize a secondary heating appliance.
When LMC is open and TT or DHW_TT is closed, the pump
shall remain off accept for post purge mode.
LMC terminals on boiler are intended to be connected to
low volt, normally closed dry contacts of the utility LMC
unit. Do not connect power to LMC terminal.
To connect utility LMC system, rst remove jumper from
LMC terminals on AT boiler control, then connect LMC unit
to terminals.
The T aux terminals can be used to energize a secondary
appliance. T Aux terminals are low voltage, normally
open and will close when LMC terminals open and there is
heating call on either R(T)-W(T) or DHW terminals .
Flow Sensor Input (FLO)
Flow sensor feature can be used to connect an installer
provided water ow sensor to de-activate the boiler if water
is not owing through the boiler (abnormal condition).
The control is equipped with an auxiliary set of contacts
(FLO) which can be used to connect a water ow sensors.
While the ow sensor terminals (FLO) are open the heating
elements are prevented from energizing and “FLO” is
displayed. The sensor input is only active while the control
is attempting to energize heating element(s). The ow
sensor input IS NOT active during the pre and post purge
modes.
The FLO terminals on the boiler are intended to be
connected to low volt, normally closed dry contacts of the
water ow sensor.
CONTROL OPERATION
To connect a ow sensor rst remove the factory installed
jumper from the FLO terminals of the AT boiler control.
Then connect the alarm output, dry contact, normally
closed terminals of the ow sensor to the FLO terminals
of the AT boiler control. Do not connect power to the FLO
terminal.
Low Water Cutoff Sensor Input (LWCO)
Low Water Cutoff Sensor feature can be used to connect
an installer provided low water cutoff sensor to de-activate
the boiler if water is not present at the sensor (abnormal
condition).
The control is equipped with an auxiliary set of contacts
(LCO) which can be used to connect a low water cutoff
sensor. While the low water cutoff terminals (LCO) are open
the heating elements are prevented from energizing and
“LCO” is displayed. The sensor input is only active while the
control is attempting to energize heating element(s). The
low water cutoff sensor input IS NOT active during the pre
and post purge modes.
The LCO terminals on the boiler are intended to be
connected to low volt, normally closed dry contacts of the
water ow sensor.
To connect a low water cutoff sensor rst remove the
factory installed jumper from the LCO terminals of the AT
boiler control. Then connect the alarm output, dry contact,
normally closed terminals of the low water cutoff sensor to
the LCO terminals of the AT boiler control. Do not connect
power to the LCO terminal.
Anti-Short Cycle Timer, heating call satised
After the completion of a comfort heating or domestic hot
water cycle, the heating elements shall remain off for a
minimum of three (3) minutes. The ASCT time begins when
the last heating element de-energizes. The pump shall be
allowed to run during the ASCT period.
Anti-Short Cycle Timer, water temperature satised
While a heating call exists (TT or DHW-TT closed) and an
element cycles off to maintain setpoint temperature, it will
not re-energize for 90 seconds.
Pump Exercising
After 24 hours of pump inactivity, the pump will turn on
for 60 seconds. Boiler must be in ON mode for pump
exercising to occur.
Non-Volatile Memory
If power is lost, after it is restored the unit will return to
the mode it was in prior to power loss. All user settings
shall be retained and restored.
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