Inputs And Outputs - Johnson Controls VMA 1410 Overview And Engineering Manuallines

VMA1400 Series Overview and Engineering Guidelines Technical Bulletin

Inputs and Outputs

Table 3: Inputs and Outputs
Input/Output Description
Analog Inputs There are two external and one internal analog inputs on the VMA1410 and four external
and one internal analog inputs on the VMA1420 and 1430. They are preset for either
temperature/setpoint or voltage. There are no jumpers to set. Shielding is not required, but if
used, earth ground the shield only at the VMA. You may use 0.6 mm (24 AWG) twisted pair
wire; however, this reduces the allowable wire length due to the resistance for Nickel (Ni),
Platinum (Pt), or Silicon (Si) sensors. To minimize sensor error caused by field wiring, the
total resistance of the nickel, silicon, or platinum resistive sensor wiring should be less than
3 ohms. The NTC sensor accepts a larger wire resistance. This wiring error effect can be
corrected through HVAC PRO software in the VMAs analog input.
Do not share the temperature/setpoint common wire (COM) with any other sensors,
transmitters, or the Zone Bus. The maximum voltage drop on the common wire must be less
than 1 mV.
Binary Inputs
There are three dry contact binary inputs on the VMA. An override button on the room
sensor initiates a Temporary Occupancy or Time Override mode of operation when pressed.
When using the TE-6700 or TE-7000 (Europe only) sensor, TempOcc shorts BI-1 directly.
Hold for 2.0 seconds.
The binary inputs on the VMA are inactive when open. They are active when you apply a
contact closure to binary input common (COM).
Analog There are two analog outputs on the VMA1420 and VMA1430. The VMA1410 has no
Outputs analog outputs. The load connects between the analog output and analog output common
(COM) terminals. Each output generates a proportional voltage output of 0 to 10 VDC. The
maximum load for each output is 10 mA with a minimum load resistance of 1000 ohms.
Note that two analog outputs are available on the VMA1430 for proportional reheat valves
or a proportional damper actuator.
Binary The VMA1410 has no external binary outputs. The VMA1420 and VMA1430 have
Outputs five external binary outputs. The damper actuator wires internally to the VMA1410 and
VMA1420. Each load connects between the BO terminal and BCOM common terminal.
These outputs switch the transformer's low side to the output allowing the relays, actuators,
or transformers to be earth grounded through Terminal 1 when needed to meet codes.
A floating/3-wire (incremental) actuator wires externally to two of the five BOs on the
VMA1430. There are only three BOs remaining for fan, box heating, supplemental heating,
and lighting.
For specific input/output range, cable length, wire size issues, refer to
the Mounting and Wiring Variable Air Volume Modular Assembly
(VMA) 1400 Series Controllers Technical Bulletin (LIT-6363125).
Note: All terminals are spade lug type except the N2 terminals,
which are removable screw terminals. Optional two-, three-, or
four-position kits (available for order) convert the spade lugs to
removable screw terminals.
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