Dwyer 616C - Manual (Page 2)

Installation
1.0 Location
Select a clean, dry mounting location free from excess vibration where
the temperature will remain between 20 and 120˚F (-6.7 and 48.9˚C).
Distance from the receiver is limited only by total loop resistance. See
Electrical Connections below. The tubing supplying pressure to the
instrument can be practically any length required, but long lengths will
increase response time slightly.
2. Position
A vertical position, with pressure connections pointing down, is
recommended. That is the position in which all standard models are
spanned and zeroed at the factory. They can be used at other angles, but
final spanning and zeroing must be done while transmitter is in that
alternate position.
Pressure Connections
Two integral barbed tubing connections are provided. They are dual-
sized to fit both 1/8˝ and 3/16˝ (3.12 and 4.76 mm) I.D. tubing. Be sure
the pressure rating of the tubing exceeds that of the operating ranges.
On ranges over 20 psi, we recommend use of a suitable hose clamp to
assure the integrity of the connection.
Electrical Connections
CAUTION: Do not exceed specified supply voltage ratings.
Permanent damage not covered by warranty will result. This unit is
not designed for 120 or 240 volts AC line operation.
Electrical connections are made to the terminal block located on the top
of the transmitter. Terminals are marked 1, 2, 3 and 4 (see Fig. B below).
Determine which of the following circuit drawings applies to your
application and wire accordingly.
Figure B
Wire Length
The maximum length of wire connecting transmitter and receiver is a
function of wire size and receiver resistance. Wiring should not contribute
more than 10% of the receiver resistance to total loop resistance. For
extremely long runs (over 1000 feet), choose receivers with higher
resistance to minimize size and cost of connecting leads. Where wiring
length is under 100 feet, hook-up 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 transmitter) must be used to power the
control loop. See Fig. C for connection 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
available 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 the negative side of the control loop after the receiver.
Otherwise, in 2-wire operation it is not necessary to observe polarity of
control loop connections.
2-Wire Connections
Figure C
3-Wire Operation
An external power supply delivering 10-35 VDC with minimum current
capability of 40 mA DC (per transmitter) is required. See Fig. D for
connection of power supply, transmitter and receiver. The range of
appropriate receiver load resistance (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 polarized, the
receiver must be connected between terminal 3 of transmitter and
negative side of power supply.
3-Wire Connections
Figure D
4-Wire Operation
An external power supply delivering 10-35 VDC with a minimum current
capability of 40 mA DC (per transmitter) or 16-26 VAC with a minimum
current capability of 80 mA AC (per transmitter) is required. See Fig. E
for connection of power supply, transmitter and receiver. The range of
appropriate load resistance (R
L
) for the DC or AC power supply available
is expressed by the formulas and graphs in Fig’s. F and G. Shielded
cable is recommended for control loop wiring. Do not employ a separate
ground in 4-wire operation. Unit will not function properly and/or damage
could result. Control loop polarity must be observed; terminal 3 is
negative and terminal 4 is positive.
SPAN AND
ZERO ADJUST
HI LO
1 2 3 4
POWER
SUPPLY
10-35 VDC
PRESSURE
TRANSMITTER
Jumper
Wire
Receiver
PRESSURE
TRANSMITTER
Receiver
POWER
SUPPLY
10-35 VDC
mA
E-43:E-43 5/24/10 4:10 PM Page 2