Dwyer Instruments 604D-0 Specifications-Installation And Operating Instructions Download Page 2

INSTALLATION
LOCATION: 

Select a location where temperature of the unit will be

between 20°F and 120°F (7°C and 49°C). Distance from the
receiver is limited only by total loop resistance. See “Electrical
Connections.” The tubing feeding pressure to the instrument can
be run practically any length required, but long lengths will slightly
increase response time. Avoid surfaces with excessive vibration.

POSITION:

All models are calibrated with the scale in a vertical

plane and units with ranges under 5 in. w.c. should only be used
in that position due to the sensitivity to gravitational forces which
cannot be corrected by zero adjustment. Higher range models can
operate in other planes but zero (both mechanical electrical) and
span adjustments may be necessary to maintain accuracy.

PRESSURE CONNECTIONS:

Two barbed connectors are pro-

vided for use with 3/16

I.D. vinyl or rubber tubing. Attach tubing

from positive pressure source to HI port. Leave LO port vented.
For negative (vacuum) pressure, connect to LO port and leave HI
port vented. For differential pressures, connect the higher to HI
port and lower to LO port.

MOUNTING:

Attach the Series 604D Indicating Transmitter to a

vertical surface using the 1

- #10 pan head sheet metal screws

provided. Mounting holes are located in upper left and lower right
corners of case.

GAGE ZEROING:

After installation, check to confirm that gage reads exactly zero
with both pressure connections open and vented to atmosphere.
If adjustment is necessary, grip case firmly with one hand and
place palm of the other hand flat on clear cover. If difficult to grip,
try placing a thin sheet of rubber between hand and cover. Rotate
counter-clockwise to remove. Zero adjust screw is located at bot-
tom of scale just to left of the indicating pointer and slightly behind
it. Use the .050

hex allen wrench included. Replace cover. 

ELECTRICAL CONNECTIONS
CAUTION: DO NOT EXCEED SPECIFIED SUPPLY VOLTAGE
RATINGS.  PERMANENT DAMAGE NOT COVERED BY WAR-
RANTY WILL RESULT. THIS UNIT IS NOT DESIGNED FOR
120 VAC or 240 VAC LINE  OPERATION.

Electrical connections to the Series 604D Indicating Transmitter
are made inside the enclosure on the left side of the unit. Remove
the cover and feed 4 conductor cable through the cable gland at
bottom of housing. Make electrical connections to the 4-screw ter-
minal block shown in Fig. B. See following instructions and draw-
ings for details on your specific application. When connections are
complete, tighten cable gland and replace cover.

Wire Length 

The maximum length of wire connecting transmit-

ter and receiver is a function of wire size and receiver resistance.
Wiring should not contribute more than 10% of receiver resistance
to total loop resistance. For extremely long runs (over 1000 ft. [305
m]), choose receivers with higher resistances to minimize size and
cost of connecting leads. Where wiring length is under 100 ft.
(30.48 m), lead wire as small as 22 AWG can be used.

2-Wire Operation 

An external power supply delivering 10-35

VDC with minimum current capability of 40 mA DC (per transmit-
ter) must be used to power the control loop. See Fig. C for con-
nection of the power supply, transmitter and receiver. Note the
jumper between terminals 3 and 4. The range of appropriate
receiver load resistance (R

L

) for the DC power supply voltage avail-

able is expressed by the formula and graph in Fig. F. Shielded two
wire cable is recommended for control loop wiring. If grounding is
required use negative side of control loop after receiver. In Fig.C
below, if power supply lead to terminal 1 is positive, ground should
be connected to wiring at right of receiver. Otherwise, in 2 wire
operation it is not necessary to observe polarity of control loop
connections.

3-Wire Operation 

An external power supply delivering 10-35

VDC with minimum current capability of 40 mA DC (per transmit-
ter) is required. See Fig. D for connection of power supply, trans-
mitter and receiver. The range of appropriate receiver load resis-
tance (R

L

) for the DC power supply available is expressed by the

formula and graph in Fig. F. Shielded cable is recommended for
control loop wiring. Do not employ a separate ground in 3 wire
operation. Unit will not function properly and/or damage could
result. Control loop polarity must be observed in the following
respect. Although power supply terminals 1 and 2 are not polar-
ized, the receiver must be connected between terminal 4 of 

transmitter and negative side of power supply.

Series 604D Indicating Pressure Transmitter

Specifications - Installation and Operating Instructions

Bulletin E-34

Page 2

ZERO ADJUSTMENT

SPAN ADJUSTMENT

TERMINAL BLOCK

1 2 3 4

SERIES 604D

PRESSURE

TRANSMITTER

POWER
SUPPLY

10-35 VDC

JUMPER

WIRE

RECEIVER

3-WIRE CONNECTION

2-WIRE CONNECTION

Fig. B

Fig. D

Fig. C

SERIES 604D

PRESSURE

TRANSMITTER

POWER
SUPPLY

10-35 VDC

RECEIVER

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