Johnson Controls VMA1400 Series Manual page 33

= Optical or
Magnetic
Isolation
24 VAC
Primary
24 VAC
AFS
Manual High
Reset Temperature
Fan
Relay
BO-1
Reheat
BO-2
Reheat
BO-3
Figure 19: VMA Internal Schematic Diagram
Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
Earth ground is required
by NEC if primary is
greater than 150 VAC.
1
XFR
2
5 BCOM
3
OPTO
4
R
6
R
8
R
COM 2
1
Stepper
µ
0.01 F
Triacs
N2
Water
Valve
3
4 In
µP = Microprocessor
µF = Microfarad
VMA
18
+15 V
26
+5 V 14
µP
AO
23
15
COM
COM
CablePRO or
CVTPRO
Laptop
33
BI
AI
AO
vmadia2