Aerco Control System (Acs); Combination Control System (Ccs) - Watts Aerco Benchmark BMK750 Operation And Service Manual

Benchmark with Edge [I]: Operation-Maintenance Manual
SECTION 6 – STANDALONE MODES OF OPERATION
Direct Drive Mode Setup Instructions
4. If Network was selected in the previous step, the Unit Address parameter appears. Enter
a valid Comm address in this parameter.
Refer to Modbus Communication Manual (OMM-0035, GF-114) for additional information.

6.5 AERCO CONTROL SYSTEM (ACS)

NOTE:
ACS is for installations with between 17 and 32 boilers. It utilizes only RS-485 signaling to the
boiler. For installations with 1 to 16 boilers Boiler Sequencing Technology (BST) is
recommended. See Section 7: Boiler Sequencing Technology.
The ACS mode of operation is used in conjunction with an AERCO Control System. The ACS
mode is used when it is desired to operate multiple units in the most efficient manner possible.
For this mode of operation, an ACS Header Sensor must be installed between 2 and 10 feet
(0.61 and 3m) downstream of the last boiler in the boiler plant's supply water header.
ACS can control up to 32 boilers via Modbus (RS-485) network communication.
For ACS programming, operation, and Header Sensor installation details, see the ACS
Operations Guide (OMM-081, GF-131). For operation via an RS-485 Modbus network, refer to
Modbus Communication Manual (OMM-0035, GF-114).
To enable the ACS mode:
ACS Mode Setup Instructions
1. As a prerequisite, verify that the unit is not a BST Client or Manager. Go to:
→ Advanced Setup → BST Cascade → Cascade Configuration,
2. On the Controller, go to:
Configuration.
3. Press Unit SH Operating Mode parameter and choose Direct Drive.
4. Press the Remote Signal parameter and choose Network.
5. Press the Baud Rate parameter and choose 9600.
NOTE:
See Section 2.11.1 in the Benchmark 750-6000 with Edge [i]: Install-Startup Manual (OMM-
0144, GF-217) for field wiring instructions.

6.6 COMBINATION CONTROL SYSTEM (CCS)

NOTE:
The ACS can be utilized for a Combination Control System.
A Combination Control System (CCS) is one that uses multiple boilers to cover both space-
heating and domestic hot water needs. The theory behind this type of system is that the
maximum space-heating load and the maximum domestic hot water load do not occur
simultaneously. Therefore, boilers used for domestic hot water are capable of switching
OMM-0145_D • GF-218 •
11/2/2020
Main Menu → Advanced Setup → Unit →Application
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
Main Menu
Unit Mode = Off.
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