Dwyer EPTA - Manual

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Dwyer Instruments, Inc.
Michigan City, Indiana EPTA Installation Instructions
P/D 080107
EPTA
INSTALLATION
READ THESE INSTRUCTIONS BEFORE YOU BEGIN INSTALLATION.
Ground yourself before touching board. Some components are static sensitive.
MOUNTING:
Circuit board may be mounted in any position. If circuit board slides out of snap track, a nonconductive “stop”
may be required. Use only fingers to remove board from snap track. Slide out of snap track or push against
side of snap track and lift that side of the circuit board to remove. Do not flex board or use tools.
POWER CONNECTIONS - THIS PRODUCT ACCEPTS 24 VDC or 24 VAC POWER.
Be sure to follow all local and electrical codes. Refer to wiring diagram for connection information. Be sure
to make all connections with power off.
1) DC Power - Refer to wiring diagram for connection information.
If the 24 VDC power is shared with devices that have coils such as relays, solenoids, or other inductors, each coil
must have an MOV, DC Transorb, or diode placed across the coil or inductor. The cathode, or banded side of the
DC Transorb or diode, connects to the positive side of the power supply.
2) AC Power - Refer to wiring diagram for connection information.
Check the wiring configuration of any other loads that may be connected to this transformer. If required by
BAS or controller specification, the 24 VAC neutral can be earth grounded at the transformer. Analog input,
digital input, and analog output circuits should not be earth grounded at two points. Any field device connected
to this transformer must use the same common. If you are not sure of other field device configuration, use
separate transformers for isolation.
If the 24 VAC power is shared with devices that have coils such as relays, solenoids, or other inductors, each
coil must have an MOV, AC Transorb, or other spike snubbing device across each of the shared coils. Without
these snubbers, coils produce very large voltage spikes when de-energizing that can cause malfunction or
destruction of electronic circuits. Refer to wiring diagram for connection information.
3) You should measure the actual voltage output of the secondary. If the output is not fully loaded you may read a higher
voltage than the circuit board can handle.
ADJUSTMENT OF GAUGES. If installation requires adjustment of the gauge for proper reading of the face, turn the gauge
no more than 1/2 turn in either direction. O rings in the bottom of the gauge port will allow this without leakage.
W arranty does not include malfunction due to clogged valve. Main air port is filtered with the supplied 80-100 micron
integral-in-barb filter (Part # A-403). Periodically check the filter for contamination and flow reduction. Replace
if needed (Part # A-403) .
The surface between the manifold and pressure transducer is a pressure seal. Minimize stress between the circuit board
and the manifold by holding the manifold in one hand while installing pneumatic tubing onto the fittings, and use care when
removing tubing to avoid damaging fittings or moving manifold.
Analog Current or Voltage to Modulated Pressure Output
and Fail Safe
(EPTA-B shown)
Bulletin L-39