Bell & Gossett HS 618B Series GT610-IP Electronic-Pneumatic Transducer - Manual (Page 3)

INSTALLATION
ELECTRICAL CONNECTION. Electric connection for this
transducer can be made in two different methods depend-
ing on the cover option chosen. The conduit connection is
1/2" NPSM.
1. Metal Cover having Top Access Cover.
Remove the top access cover and connect the positive
wire to Terminal No. 2 and the negative wire to Terminal
No. 1 for direct acting mode. For reverse acting mode,
reverse the input leads.
2. Metal Cover without Top Access Cover.
This option provides two (2) leads 18" (457mm) long
(#18 GA. wire). (Positive - RED) - (Negative - BLACK).
CAUTION: Exercise care when installing lead wires.
Accidental contact of screwdriver to metal cover may
cause short.
IMPORTANT: Remove all metal chips from conduit
before installation to prevent malfunction of the
coil/magnet assembly.
RANGE SELECTOR SWITCH. GT610-IP Series incorpo-
rates a range selector jumper switch which can be posi-
tioned to accept a 4-20 or 10-50 mA DC input signal on
the milliampere circuit board or a 0-5 or 1-9 VDC input
signal on the voltage board.
PNEUMATIC CONNECTIONS. Connect the supply pres-
sure tubing to the 1/4" (8mm) NPT inlet (marked "IN"). A
clean, filtered air supply of 35 Psig (241 kPa) is required
for the 6-30 Psig (41-207 kPa) outputs. A supply pressure
up to 100 psi (690 kPa) may be used if desired. To pre-
vent contamination of the internal section of the transduc-
er, a Filter Regulator Valve (Part Number 402722) is rec-
ommended. The 1/4" (8mm) NPT outlet (marked "OUT")
delivers a pneumatic signal in proportion to the mA DC
input signal.
ADJUSTMENTS
Should field adjustments be required, use the following
calibration procedure:
1. Connect the recommended air supply to the inlet of the
transducer and a pressure gauge to the outlet.
2. Connect the electrical input and set the input to the 0%
value (e.g., 4 mA for a 4-20 mA unit).
3. Observe the output pressure. Adjust if necessary by
turning the external zero adjust located on the side of
the transducer above the output gauge connection
(marked G1).
4. Increase the electrical input signal to the 100% value.
5. Observe the output pressure. Adjust if necessary by
turning the range potentiometer on the circuit board to
obtain the required output. The range potentiometer is
accessible by removing the rubber grommet on the front
of the housing. Turning the range potentiometer clock-
wise decreases the span.
6. The zero and range adjustments are interactive. After
adjusting the range potentiometer it will be necessary
to recheck the zero. Repeat steps 2 through 5 until
both end-points are at the required values.