13
Electronic Expansion Valve (EXV) Board —
The 30XW150-325 units have one EXV board. The
30XW350,400 units have one EXV board per circuit. See
Fig. 10. The board is responsible for monitoring the suction gas
temperature and economizer gas temperature thermistors. The
board also signals the main EXV and economizer EXV
(ECEXV) motors to open or close. The electronic expansion
valve board responds to commands from the MBB and sends
the MBB the results of the channels it monitors via the LEN
(Local Equipment Network). See below for DIP switch infor-
mation. See Tables 6 and 7 for EXV inputs and outputs.
EXV BOARD 1
(150-400)
DIP SWITCH
1
2
3
4
5
6
7
8
Address:
ON
ON
ON
ON
ON
ON
OFF
ON
EXV BOARD 2
(350,400)
DIP SWITCH
1
2
3
4
5
6
7
8
Address:
OFF
ON
ON
ON
ON
ON
OFF
ON
1
2
3
4
5
6
7
8
ON
100
100
257-01
712
100K
100K
100
1
2
3
4
5
3
2
1
-
G +
J3
1
2
3
4
5
J2A
EXV
A
J2B EXVB
24VAC
STATUS
MOV1
LOCATION OF
SERIAL NUMBER
43
2
1
THA
THB
D4
D6
J1
C15
C16
D5
U5
Q2
Q1
L4
U4
12/11
C17
+
Q45
Q42
Q37
G2
Q35
Q25
Q27
Q30
Q20
Q22
Q17
Q15
Q12
Q10
C10
Q7
S1
C1
1
U2
D2
L1
U1
C37
C39
SB
D15
U6
C25
C49
Q4
Q5
L2
R2
R3
L3
D1
R9
TEMP
D29
D9
D8
SI0
(LEN)
COMM J4
DIP
SWITCH
Fig. 10 — EXV Board
a30-4216