AERCO Control System (ACS)
CHAPTER 2
: ACS Installation
Page 26 of 139
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, New York 10913
11/22/2017
GF-131
Phone: 800-526-0288
OMM-0081_0F
METHOD B
– TERMINATION ACTIVATED AT I/O BOX
Figure 2-7: RS485 (Modbus) Wiring For Benchmark Series Boilers (Sheet 2 of 2)
NOTE
Do not terminate the shields of
the RS485 leads to the ground
(GND) terminal. The shields
must be terminated at the
source ends only. Connect the
shields of the incoming and
outgoing RS485 leads
together.
Connect 120 OHM,
½ Watt resister
b and –
RS485 terminals on
the LAST C-More
Box.
I/O Board
OPEN DOOR TO
ACCESS I/O BOX
BENCHMARK
DO NOT USE
THESE TERMINALS
RS485
CONNECTIONS
(SEE NOTE)