I/O Board Connections - Watts AERCO Benchmark BMK750 Installation And Start-Up Manual

Benchmark Platinum-Edge [ii]: Installation Manual
SECTION 2 – INSTALLATION
FLOW SENSOR
BLOWER RELAY
I/O BOARD POWER
HARNESS 63232
CONNECTOR J24
40 PIN RIBBON I/O
HARNESS 63220
CONNECTOR J1

2.11.1 I/O Board Connections

The I/O board contains the terminal listed below, arranged on removable, named connector
strips J3 through J7 and J14, plus Molex connectors for unit harnesses. The maximum gauge
of wires connecting to the I/O board is 14.
12 V
Ground
• GF-210 •
OMM-136_G
4-20mA OUT
PUMP RELAY
Figure 2-11: Secondary Power Panel Terminals
LOW WATER CUTOFF JUMPER
CONNECTOR J8
Figure 2-12: I/O Board Cable Connections
Ignition Transformer
Ignition
Transformer
J24
Current Sense
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
8/20/2020
OXYGEN SENSOR
AIR PUMP
(AIR EDUCTOR ON BMK5000 &
6000 ONLY)
BLOCKED FLUE
SWITCH
30 PIN RIBBON I/O HARNESS 63221
CONNECTOR J2
Line Voltage
AC Hot
AC Neutral
Neutral
J9
SPARK MONITOR
FROM SHELL
HARNESS 63216-2
CONNECTOR J9
DUAL FUEL SWITCH
HARNESS 63239
(DUAL FUEL ONLY)
CONNECTOR J10
VALVE HARNESS
INTERLOCK FROM SHELL
HARNESS 63216-2
J6 PINS 3 & 4
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