Aerco Benchmark 2.0 LN User Manual

Benchmark 2.0 LN Installation, Operation & Maintenance Manual
CHAPTER 2 – INSTALLATION
Page 28 of 168 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0046_0J
06/18/2015 Phone: 800-526-0288 GF-123
2.10.4 B.M.S. (PWM) IN (4)
NOTE
Only BMS Model 168 can utilize Pulse Width Modulation (PWM), not the BMS
II or ACS (AERCO Control System).
These terminals are used to connect the AERCO Boiler Management System (BMS) to the unit.
The BMS utilizes a 12 millisecond, ON/OFF duty cycle. This duty cycle is Pulse Width Modulated
(PWM) to control valve position. A 0% valve position = a 5% ON pulse and a 100% valve position
= a 95% ON pulse.
2.10.5 Shield (5)
The SHIELD terminals are used to terminate any shields used on sensor wires connected to the
unit. Only shields must be connected to these terminals.
IMPORTANT
DO NOT USE the mA OUT output to remotely monitor Setpoint, Outlet Temp
or Fire Rate Out.
2.10.6 mA Out (6)
These terminals provide a 4 to 20 mA output to the VFD (if so equipped) to control the rotational
speed of the blower. This function is enabled in the Configuration Menu (Chapter 3, Table 3-4).
2.10.7 RS-485 COMM (7)
These terminals are used for RS-485 MODBUS serial communication between the unit and an
external “Master” such as a Boiler Management System (BMS), AERCO Control System (ACS),
Energy Management System (EMS), Building Automation System (BAS) or other suitable device.
2.10.8 TxD, RxD (8)
These terminals provide a parallel connection to the connector on the C-More Controller front
panel, for connecting a computer or laptop.
2.10.9 VFD/Blower (9)
These terminals provide a 0 to 10 volt output to control the rotational speed of the blower. This
function is enabled in the Configuration Menu (Chapter 3, Table 3-4).
2.10.10 Exhaust Switch In (11)
These terminals permit an external exhaust switch to be connected to the exhaust manifold of the
boiler. The exhaust switch should be a normally open type switch (such as AERCO Part No.
123463) that closes (trips) at 500°F.
2.10.11 Interlocks (10, 12)
The unit offers two interlock circuits for interfacing with Energy Management Systems and auxiliary
equipment such as pumps or louvers. These interlocks are called the Remote Interlock and
Delayed Interlock (Figure 2-10). The wiring terminals for these interlocks are located inside the I/O
Box on the unit front panel. The I/O Box cover contains a wiring diagram which shows the terminal
strip locations for these interlocks (REMOTE INTL’K IN and DELAYED INTL’K IN). Both interlocks,
described below, are factory wired in the closed position.

Aerco Benchmark 2.0 LN Specifications

General

Brand	Aerco
Model	Benchmark 2.0 LN
Category	Boiler
Language	English