Benchmark 5000-6000 Operation & Maintenance Manual
SECTION 6
– AERTRIM OPERATION
OMM-0118_B
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GF-203
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5/9/2019
Technical Support
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SECTION 6:
AERTRIM OPERATION
6.1 AERtrim INTRODUCTION
Advanced combustion control systems need to maintain precise air/fuel ratios to maximize
efficiency. Gas and oil-fired boilers often deviate from the ideal air-fuel ratio due to
environmental variations such as humidity, atmospheric pressure, filter dust loading, delivered
gas energy content and other factors. If the boiler is operating with fixed blower/damper
positions, the air/fuel ratio will normally vary within an acceptable level, but will not be truly
optimized for efficiency and reliability.
The AERtrim system is designed to measure and maintain an ideal air-fuel ratio in the
Benchmark line of boilers, thus maximizing efficiency and reliability while minimizing emissions.
It does this by first measuring post combustion oxygen percentages inside the combustion
chamber. This data is fed through the Electronic Control Unit (ECU) which is connected to the
C-More Controller inside the boiler. If the oxygen readings are outside of preset or user defined
values, the blower voltage is changed in small increments until the readings fall within the ideal
range.
A simplified representation of the system is shown in Figure 6-1.
Figure 6-1: Simplified AERtrim Diagram
6.2 AERtrim ACTIVATION
If you purchased the AERtrim system as part of your boiler, it was activated at the factory prior
to shipping the unit. However, if you are retrofitting the AERtrim system on a unit that was
shipped without it, or if the C-More Controller is changed for any reason, you must activate the
AERtrim function by completing the procedures below. Note that the activation code for each
unit is unique, and thus cannot be transferred to any other unit;
if you have multiple units, you
must take care to install the correct code on the correct unit
.
Combustion Chamber
O
2
Sensor
Sensor ECU
C-More Controller
Blower
Voltage
Output
Oxygen Input
Burner
CanBus
CanBus
