Instruction Manual

Benchmark 750/1000 Boiler Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
OMM-0082_0J AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 33 of 192
GF-130 Ph.: 800-526-0288 05/21/2014
2.13 DUCTED COMBUSTION AIR
The AERCO Benchmark 750 & 1000 MBH Boilers are UL listed for 100%-ducted combustion.
For ducted combustion air installations, the screen inlet air ductwork must then be attached
directly to the unit’s air inlet.
In a ducted combustion air application, the combustion air ducting pressure losses must be
taken into account when calculating the total maximum allowable venting run. See the AERCO
Benchmark Venting and Combustion Air Guide, GF-2050. When using the heater in a ducted
combustion air configuration, each unit must have a minimum 6 inch diameter connection at the
unit.
2.14 BENCHMARK PUMP RELAY OPTION
An optional Benchmark pump relay allows the user to turn a pump on/off and open/close a
motorized valve as the boiler cycles on and off on demand. The Pump Delay Timer feature
allows the user to keep the pump running and keep the motorized valve open for up to 30
minutes after the boiler has shut down and the demand is satisfied.
The Benchmark pump relay (SPDT) contact is rated for:
• 10 A Resistive @ 277 VAC/28 VDC
• 1/3 HP N/O @ 120/240 VAC
• 1/6 HP N/C @ 120/240 VAC
• 480 VA Pilot Duty @ 240-277 VAC
If pump/valve load exceeds the above contact ratings, use a separate contact relay.
See Figures 2-13 and 2-14 for wiring details.
To identify if the boiler is equipped with the BMK Pump Relay Option (part no. 69102), look for
the label and relay as shown in Figure 2-15.
Figure2-13: Schematic – System Pump Start using Boiler Pump Relay