2.2
Power Entry and Control Module
2.2.1
PECM Overview
Overview
The PECM3-CTL board mounts on the PECM-SSR board. This assembly provides a variety
of power and control functions. The connections are shown below.
AC in
Optional
UPS input
for 24vdc
supply
LWH1 - LWH5
out
MWH out
Purge Air
Switch
24v in
Fan
power
HWH SSR
control out
I
2
C bus
I
2
C bus
Solenoid
control out
Atmospheric
pressure sensor
Air bath heater
monitor in
(Ribbon-cable
connector to
PECM-SSR)
Purge signal out
LW
H/M
WH
co
ntro
l in
HW
H co
ntro
l ou
t
HW
H co
ntr
ol i
n
HW
ou
H co
nt
con
tro
l
HW
HW
HW
H
H
H
co
co
co
nt
nt
nt
nt
nt
ro
ro
ro
rol
con
tro
TL/
OT
mo
dul
es
Temp RTD in
Filtered
AC out
to 24v
supply
L1 MMI
LED out
MWH
HWH SSR
power out
PECM-SSR Board
PECM3-CTRL Board
F1
F1
F5
F2
F5
F5
F2
F2
F2
F2
F2
F2
F2
F2
F2
F2
F2
F2
F2
F4
(wit
hou
t co
ver)
Board
cov
er)
(wit
hou
t co
v
F4
(wit
ho
F4
(wit
hou
t
F3
(wit
hou
t co
ver)
Purge disable jumper
Figure 2-4
PECM3 I/O Connections
The PECM3 assembly part number is 2021828-002. An upgrade kit, part number 2022019-001
is available to replace earlier units.
Electronic Compartment Component Descriptions and Maintenance Procedures
2.2 Power Entry and Control Module
Maxum II Reference Manual
18
Manual, 7/2017, 2000596-001