Johnson Controls VMA 1400 Series User manual

Technical Bulletin
Issue Date 11/01/01
© 2001 Johnson Controls, Inc. www.johnsoncontrols.com
Code No. LIT-6363125
TECHNICAL BULLETIN
Mounting and Wiring Variable Air Volume Modular
Assembly (VMA) 1400 Series Controllers
Mounting and Wiring VMA1400 Series Controllers ...........................3
Introduction......................................................................................................... 3
Key Concepts...................................................................................................... 4
VMA Position and Orientation..........................................................................................4
Damper Actuator Direction to Close ................................................................................4
N2 Address Switches ......................................................................................................4
Wiring and Cabling Precautions ......................................................................................5
General Wiring Information..............................................................................................6
Power Source Wiring.......................................................................................................6
Phone Jack Polarization ................................................................................................10
Sensor Interfaces ..........................................................................................................11
Procedure Overview......................................................................................... 14
Detailed Procedures......................................................................................... 16
Preparing the VMA for Mounting....................................................................................16
Mounting the VMA1410/1420 ........................................................................................18
Mounting the VMA1430 .................................................................................................18
Setting the Damper Position (VMA1410, 1420, or VMA1430 with External Actuator).....19
Wiring the VMA .............................................................................................................21
Connecting the N2 Bus..................................................................................................24
Reference Information ..................................................................................... 26
VMA Wiring List.............................................................................................................26
VMA Single Duct Application Wiring Diagram................................................................28
VMA Single Duct Supply/Exhaust Wiring Diagram ........................................................29
VMA Dual Duct Application Wiring Diagram ..................................................................30

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
2
VMA Internal Schematic Diagram..................................................................................32
Fabricating Your Own Interconnection Cable.................................................................34
Troubleshooting ............................................................................................... 35
Troubleshooting VMA Room Temperature Drift .............................................................35

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin 3
Mounting and Wiring VMA1400
Series Controllers
Introduction
The integrated VMA1410/1420, which includes a controller, actuator,
and pressure sensor, mounts on the Variable Air Volume (VAV)
terminal box. The VMA1430 mounts anywhere on the VAV box and
is wired to a separate damper actuator.
Note: This document focuses on the VMA1410, 1420, and 1430
controllers. The VMA1400 Series also includes the
VMA1440, which is a controller used exclusively as part of
the Metasys® Zoning Package. See the Metasys Zoning
Package Product Bulletin (LIT-639050) and the Metasys
Zoning Package Overview Technical Bulletin (LIT-639100)
for information on this specialized product.
Instructions for wiring the VAV Modular Assembly (VMA) and its
accessory devices are provided in this section.
This document describes how to:
•prepare the VMA for mounting
•mount the VMA1410/1420
•mount the VMA1430
•set the damper position (VMA1410, 1420, or VMA1430 with
external actuator)
•wire the VMA
•connect the N2 Bus

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
4
Key Concepts
VMA Position and Orientation
Consider the following when positioning and orienting the VMA:
•Mount the VMA on a vertical and flat surface where it functions
best, such as the side of the VAV box.
•Route the tubing so a portion of it is lower than the pressure
sensor, or loop the tubing. This creates a moisture trap that
prevents any condensation from entering the sensor.
•Do not make any sharp bends in the tubing. This could collapse the
tube and block the pressure path.
•Verify wiring terminals are accessible.
•Ensure that no extra mounting brackets, linkage, or couplers are
required for standard mounting.
•Locate the VMA so that it has adequate clearance for future
servicing and is protected from moisture and corrosive fumes.
Damper Actuator Direction to Close
The damper actuator direction to close is established upon installation
of the VMA, using HVAC PROsoftware. The damper must be
manually positioned to allow the VMA actuator to fully open and
close the damper. Incorrect damper positions in a zone can lead to
misdiagnosed readings, resulting in unnecessary repetition of setup
and diagnostics.
N2 Address Switches
It is best, from an accessibility standpoint, to set the N2 switches
before mounting the VMA. The switches, located on the side of the
VMA, are set to On for the address numbers indicated on the room
schedule or building drawings. Use Addresses 1-253 only.
Addresses 0, 254, and 255 are reserved. Refer to the Preparing the
VMA for Mounting section in this document for further information.
If software addressing is used, N2 switches must be set to 0 or 255.
See the HVAC PRO User’s Guide for details on software addressing.

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin 5
Wiring and Cabling Precautions
!
WARNING: Possible Equipment Damage or Electrical
Shock.To avoid damaging equipment or
possible electrical shock, ensure that all power
supplies to the system are disconnected prior to
wiring.
!
CAUTION: Shorting of Binary Outputs (BOs) while
energized will destroy the VMA output triac.
Read these precautions before touching the terminals or wiring the
VMA and its accessories:
•Make all wiring connections in accordance with the National
Electrical Code (NEC) and state and local regulations. For
transformer primaries above 150 VAC, the secondary must be
earth grounded at the transformer to meet NEC. Terminal 1 can be
earth grounded. Grounding on Terminal 1 results in 24 VAC being
applied to DCOM with respect to earth.
Note: 24 VAC to 24 VAC isolation transformers are not necessary.
The power supply is internally isolated. For specific methods
for wiring the VMA to meet Underwriters Laboratories, Inc.
(UL) 864 requirements, refer to the Metasys Smoke Control
Wiring Technical Bulletin (LIT-636331).
•Terminal 3 is an earth ground connection (optional).
•Locate equipment and route the wiring so that twisted pair signal
wiring is separated from power wiring by at least 150 mm (6 in.).
•Make all wiring connections to the VMA using only copper
conductors. To establish tight, reliable electrical connections, use
the correct wire sizes for the terminals. Avoid very thin solid
wires, such as 26 AWG or less than 0.6 mm, which tend to break.
•Daisy chain the N2 Bus. The use of Y or T connections without a
repeater installed as the T-tap may cause a loss of communications.
Make sure that there is at least one End-of-Line termination on the
N2 Bus (usually at the Network Control Module [NCM] or N30).

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
6
•Do not run N2 Bus, Zone Bus, Analog Input (AI), Binary Input
(BI), Analog Output (AO), or Binary Output (BO) wiring in the
same conduit as line voltage wiring (above 30 VAC), or with
wiring that switches power to highly inductive loads such as
contactors, coils, motors, or generators.
•Run Zone Bus, AI, AO, and BI wiring in the same bundle or
conduit where convenient. If the BO wiring is not wired through
other switches or contacts, such as actuator end-of-travel switches,
bundle it with the other Input/Output (I/O) wiring where
convenient.
General Wiring Information
The following are general wiring considerations:
•The VMA includes isolated N2, isolated binary outputs, and
isolated 24 VAC.
•The 24 VAC power input is internally transformer isolated by the
VMA. To meet NEC requirements for line voltage greater than
150 VAC, Terminal 1 can be earth grounded.
•Up to ten cooling-only controllers (VMA1410) can be powered
from one 100 VA low voltage power limited, Class 2 transformer.
See Power Source Wiring below for more information. Conduit is
not required by the NEC for Class 2 wiring installations.
•Large insulated spade lugs with a polarizing tab (for high voltage)
do not fit on the VMA.
Power Source Wiring
To calculate the number of VMAs that can be powered from
one 100 VA unit, use the equation below. In this equation, the value
TotalVA equals the total VA consumed by the VMA, actuator, and
output loads.
VATotal
100
rTransformeVA100perVMAs =
Table 1 shows the power rating for each cooling/heating coil valve
actuator. The valve power plus the VMA power (1410/1420 = 10 VA;
1430 = 3 VA) must not exceed 100 VA. If a device is not listed in
Table 1, refer to the product literature for that device.

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin 7
Table 1: Actuator VA Power Rating
Actuator Type Power Rating
VA-8020 Incremental 4 VA
VA-8050 Incremental 6 VA
VA-7150 Incremental 2.7 VA
VA-7153 Incremental w/feedback 2.7 VA
J Series Electric Zone Valve On/Off 7 VA
VA-8022 Voltage (0 to 10 VDC) 4 VA
VA-8052 Voltage (0 to 10 VDC) 6 VA
VA-7152 Voltage (0 to 10 VDC) 4.7 VA
VA-7200 Incremental 6.7 VA
VA-7203 Incremental w/feedback 6.7 VA
VA-7202 Voltage (0 to 10 VDC) 8.7 VA
GE RR-7 or Touchplate Lighting relay 42 VA for 50 ms *
VA-7450 Incremental 2.5 VA
VA-7452 Voltage (0 to 10 VDC) 2.5 VA
VA-7040 Thermal (DAO) 3 VA
VA-7310 Incremental 2 VA
VA-7312 Voltage (0 to 10 VDC) 2 VA
VA-7010 On/Off 7 VA
M9104-AGA-2N Incremental 3.4 VA
M9104-AGA-2 Incremental w/conduit 3.4 VA
M9104-AGS-2N Incremental w/DPT-2015 3.4 VA
M9104-GGA-2 Proportional 0-10V 5 VA
M9104-GGC-2 Proportional 0-10V
w/conduit
5 VA
* Do not schedule all lights on one transformer to turn on at the same time. The
current surge on the transformer could open the circuit breaker.
When using a single transformer to power multiple VMAs, use a wire
gauge large enough to handle the current and minimize the voltage
drop. The voltage drop depends on the current draw, wire gauge, and
wire length. On a fully loaded 100 VA transformer, a 120 VAC
primary draws only 0.8 amperes, while the 24 VAC secondary draws
4 amperes.
The standard 2.5 mm2(14 AWG) cable (Example 1 in Figure 1) is
limited to 27m (88 ft) with ten cooling-only VMAs, all at one end of
the cable. If the transformer is centered (Example 2 in Figure 1) with
five VMAs on the left and five VMAs on the right, the distance in
each direction can be increased. This is because both the current
and voltage drop are halved. In this example, both the left and the right
legs could be increased to 54m (176 ft) from the transformer
(50 VA from each leg), creating a 108m (352 ft) total length.

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
8
< 88 ft of 14 AWG >
24 VAC
< 176 ft of 14 AWG > < 176 ft of 14 AWG >
100 VA
24 VAC
100 VA
VMA
VMA
VMA
VMA
VMA
VMA VMA
VMA
VMA
VMA VMA
VMA VMA VMA
Example 1: All ten VMAs are at one end.
Example 2: Transformer is centered.
VMA
VMA
VMA
VMA
VMA VMA
Cable_lg
Figure 1: Power Cable Lengths
There are two ways to connect power and loads to the VMA.
Individual spade lugs accept a single 4 mm2to 0.8 mm
(10 to 22 AWG) wire and fit on 6 mm (1/4 in.) tabs, or optional screw
terminals can be assembled over the spade lugs. The screw terminals
accept up to a single 4 mm2(12 AWG) wire or two 2.5 mm2
(14 AWG) wires. When two wires are crimped into one spade lug, a
wire nut (to connect two heavy wires to a short 152 mm [6 in.] thinner
wire) or a larger spade lug barrel is needed.

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin 9
The following tables indicate the relationship between cable length
and power at the end of wires.
Table 2: Maximum 24 VAC Secondary Cable Length for Given Power/Gauge
(U.S. Measurements)
Cable Size
8 Gauge 10 Gauge 12 Gauge 14 Gauge 16 Gauge 18 Gauge
Power (VA) at
End of Wire Cable Length (ft)
10
3520 2200 1400 880 550 350
20
1760 1110 700 440 275 175
30
1173 740 467 293 183 117
40
880 555 350 220 138 88
50
704 444 280 176 110 70
60
587 370 233 147 92 58
70
503 317 200 126 79 50
80
440 278 175 110 69 44
90
391 247 156 98 61 39
100
352 222 140 88 55 35
Table 3: Maximum 24 VAC Secondary Cable Length for
Power/Wire Gauge (Metric Measurements)
Cable Size
4 mm22.5 mm21.5 mm2
Power (VA) at
End of Wire Cable Length (Meters)
10
427 268 168
20
213 134 84
30
142 89 56
40
107 67 42
50
85 54 34
60
71 45 28
70
61 38 24
80
53 34 21
90
48 30 19
100
43 27 17

Mounting and Wiring VMA1400 Series Controllers Technical Bulletin
10
Phone Jack Polarization
Figure 2 illustrates the polarization of the 6-pin and 8-pin phone jacks
on the VMA or room sensor (TE-6700 or TMZ1600). Pin 1 is to the
extreme left as you face the jack opening, tab notch down.
Note: If you need to create your own cable, refer to Fabricating
Your Own Interconnection Cable in the Reference
Information section of this document. Otherwise, order
pre-terminated cables.
8-pin 6-pin
VMA Room Sensor
phonejac
Pin 1
Figure 2: Phone Jack Polarization
Table 4: TE-6700 Phone Jack Pin Identification
8-Pin Phone Jack on VMA 6-Pin Phone Jack on TE-6700
Pin Signal Pin Signal
1BI-1 Temp Occ 1Not used
2AI 2 Zone Setpoint 2+15 VDC
3AI 1 Temperature Sensor 3COM
4COM for AI-1 4Not used
5+15 VDC 5Zone Bus (ZB)
6ZB COM/LED BI COM 6Not used
7COM for AI-2
8ZB+
Table 5: TMZ Phone Jack Pin Identification
8-Pin Phone Jack on TMZ 6-Pin Phone Jack on TMZ
Pin Signal Pin Signal
1Not used 1Not used
2Not used 2+15 VDC
3AI1, Zone Temperature Sensor 3COM
4AI1, Sensor Common 4Not used
5+15 VDC 5Zone Bus (ZB)
6Supply/Zone Bus Common 6Not used
7Not used
8Zone Bus