Dwyer PBLTX User Manual
Page 2
5. Wiring
An external power supply delivering 10-28 VDC with minimum
current capability of 40 mA DC (per transducer) is required to
power the control loop. See Fig. A for connection of the power
supply, transducer and receiver. The range of appropriate re-
ceiver load resistance (RL) for the DC power supply voltage avail-
able is expressed by the formula:
RL Max =Vps – 10V
20 mA DC
Shielded cable is recommended for control loop wiring.
Black wire is negative (-) and red wire is positive (+) in Fig. B.
MAINTENANCE
After final installation of the pressure transducer and its compan-
ion receiver, no routine maintenance is required. A periodic check
of system calibration is suggested. The Series PBLTX transduc-
ers are not field repairable and should be returned if repair is
needed (field repair should not be attempted and may void war-
ranty). Be sure to include a brief description of the problem plus
any relevant application notes. Contact customer service to re-
ceive a return goods authorization number before shipping.
CAUTION: Do not exceed specified supply
voltage ratings. Permanent damage not cov-
ered by warranty will result. This device is not
designed for 120 or 240 volt AC operation.
Use only on 10 to 28 VDC.
INSTALLATION
1. Location: Select a location where the temperature of the trans-
ducer will be between 0 and 176°F (-18 to 80°C). Distance from
the receiver is limited only by total loop resistance.
2. Position: The transducer is not position sensitive. However all
standard models are originally calibrated with the unit in a posi-
tion with the diaphragm downward. Although they can be used at
other angles, for best accuracy it is recommended that units be
installed in the position calibrated at the factory.
3. Mounting: The transducer can be mounted via several meth-
ods. It can be suspended from the electrical cable, it can be
placed resting on the bottom of the tank in either horizontal or
vertical orientation, or it can be attached to a pipe or hang wire by
the 1/2˝ NPT male connection on the top of the housing.
4. Wire Length: The maximum length of wire connecting the
transducer and receiver is a function of wire size and receiver re-
sistance. Wiring should not contribute more than 10% of the re-
ceiver resistance to total loop resistance. For extremely long runs
(over 1000 feet), choose receivers with higher resistance to min-
imize the size and cost of connecting leads. Where wiring length
is under 100 feet, wire as small as 22 AWG can be used.
POWER
SUPPLY
10-28 VDC
-
RECEIVER
BLACK
RED
PRESSURE
TRANSDUCER
mA
Fig. A
Fig. B
BLACK (-)
RED (+)