AERCO BMS II BOILER - Manual (Page 81)

APPENDIX E
E-1
APPENDIX E
_____________________________
BMS II WIRING DIAGRAM
1
11
2
3
4
5
6
+
7
-8
9
10
12
13
14
OUT
AIR
SENS
HDR
SEN
4-20
MA
INT1
INT2
SET
BACK
485 ISO GND
485 B +
485 A -
RXD
TXD
ISO 12 V
FLT
ALARM
AUX
N
L
SYS
START
SHLD
RTN
85
–
265
VAC
TERMINALS
PROVIDE
12
VDC
@
15
mA
RELAYS RATED AT
120
VAC
,
5
A
&
FUSED
INTERNALLY AT
5
A
232 ISO GND
OUTSIDE AIR SENSOR
HEADER TEMP SENSOR
RETURN TEMP SENSOR
4 – 20 mA WHEN UTILIZED
CONTACT CLOSES ON
OUTSIDE AIR TEMP
CONTACT CLOSES ON
BMS FAULT CONDITION
CONTACT CLOSES WHEN
HEATING PLANT IS AT
MAX. POWER INPUT POWER INPUT
,
16
AWG
120
VAC
,
60
Hz
,
1
A
FUSED INTERNALLY
AT
1
A
SENSOR WIRING
(NOTE
1
)
INTERLOCKS
&
SETBACK WIRING
(NOTE
2
)
NOTES
:
1
.
AERCO RECOMMENDS USING TWO
-CONDUCTOR
,
TWISTED
,
SHIELDED PAIR
,
22
AWG CABLE
(BELDEN
9841
OR EQUIV
.)
-
TERMINATE SHIELDS AT BMS SHIELD
(SHLD
)
TERMINAL ONLY
.
-
DO NOT CONNECT SHIELDS AT SENSOR ENDS
.
-
DO NOT RUN SENSOR WIRING WITH POWER WIRING
.
2
.
CONTACTS PROVIDED BY OTHERS
.
USE CONTACTS RATED FOR
LOW SIGNAL LEVELS
.
JUMPER INTERLOCKS
(INT
1
,
INT
2
)
IF EXTERNAL CONTACTS ARE NOT USED
.
3
.
IF THE EMS BEING USED CONTAINS ONLY A RS
485
PORT
,
A RS
485
-TO
-RS
232
CONVERTER IS REQUIRED
.
IF NECESSARY
,
A
12
VDC OUTPUT IS PROVIDED
BY THE BMS II TO POWER THE RS
485
-TO
-RS
232
CONVERTER
,
RS
485
TO
BOILERS
RS
232
FROM EMS
(NOTE
3
)
TO SHLD
(TERM . 3 )
IF NEEDED (NOTE 3)