Aerco Benchmark Series User Manual

CONTROL PANEL OPERATING PROCEDURES
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3-6
DURING
IGNITION TRIAL
the end of the trial for
ignition period.
LOCKOUT RUN
AIR FLOW
The air pressure switch
opened after flame was
proven.
LOCKOUT RUN
FLAME
Flame signal was lost
after flame was proven.
LOCKOUT RUN
The combustion
safeguard is locked out.
3.5.3 ANNUNCIATOR START
SEQUENCE MESSAGES
The following table lists the annunciator MAIN
display start sequence messages.
STANDBY
The unit is in standby
mode waiting for a call
for heat
PURGING
The unit is in the 7-sec.
purge.
IGNITION TRIAL
The unit is in 10 second
ignition position,
attempting to light the
burner
FLAME PROVEN
The unit has
established flame and
is firing.
3.6 THE COMBUSTION SAFEGUARD
The Combustion Safeguard is responsible for
monitoring the safety components during the
start sequence and after flame is established. It
is also responsible for the timing of the start
sequence, including the purge and ignition
cycles.
The combustion safeguard is located in the
bottom of the control panel as shown in Figure
3.9. There are five status LED’s that indicate the
status of operation. These lights are redundant
to messages displayed by the annunciator. and
are useful as a double check on the annunciator.
The table below defines the function of each
LED’s. A reset button located on the combustion
safeguard is used to reset it after a lockout. The
combustion safeguard will shut the unit down if
one of the following occurs:
DESCRIPTION
FUNCTION
POWER
Lights when the limit string
is satisfied and there is a
call for heat.
PILOT
Lights when the air flow
circuit is satisfied.
FLAME
Lights during the trial for
ignition period.
MAIN
Lights once flame has
been detected.
ALARM
This lights when the
controller is in a
LOCKOUT condition.
3.9
Combustion Safeguard Status Indicator LED
Location
Note:
After resetting the combustion safeguard
the Annunciator must also be reset using
the CLEAR button.
3.7 WATER LEVEL TEST and RESET
SWITCHES
The water level switches are located on the left
side of the control box (see Fig. 3.10). When
depressed, the TEST switch simulates a low
water level condition by breaking the connection
between the water level probe and the sensing
circuitry. To test the low water level circuitry
depress the test switch for 3 seconds. The unit
should fault resulting in the red fault light blinking
and the LED display showing LOW WATER
LEVEL.
Note:
Only water level circuitry is tested during the
above test. The water level probe is not
tested. To determine if the probe is
functioning properly, the water level must be
reduced below the level of the probe.
To reset the unit, depress the water level reset
switch, the annunciator CLEAR button, and if
necessary, the reset button on the combustion
safeguard.

Aerco Benchmark Series Specifications

General

Model	Benchmark Series
Category	Boiler
Manufacturer	Aerco
Vent Material	Stainless Steel
Fuel Type	Natural Gas
Operating Pressure	160 psig
Control System	Aerco Control System
Heat Exchanger Material	Stainless Steel