Det-Tronics PIRVOLHV Volumetric Infrared Hydrocarbon Gas Process Monitor for Heavy Hydrocarbons - Manual (Page 9)

7 3 .1 95-8632
DETECTOR SEpaRaTION (OpTIONaL)
In applications where the PIRVOLHV must be installed
in a different location from a control device (such as a
transmitter), a PIRTB termination box must be installed at
the PIRVOLHV location to make the electrical connection.
Refer to Figure 11 for a typical separation diagram.
Wiring Requirements for Detector Separation
Shielded four wire cable is recommended for connecting
the PIRTB to the transmitter. Cable with a foil shield is
recommended. The shield of the cable should be open
at the PIRTB and connected to earth ground at the
transmitter termination box. Ensure that the shield wire is
clipped short and insulated with electrical tape to prevent
accidental grounding at the open end.
The maximum distance between the PIRTB and the
transmitter is limited by the resistance of the connecting
wiring, which is a function of the gauge of the wire being
used.
NOTE
It is important to maintain a minimum of +18 volts
dc (including ripple) at the PIRVOLHV. When
determining the appropriate wire size for the
installation, refer to Figure 2. Be sure to take into
account the distance from the power supply to
the PIRVOLHV or to the transmitter and then to the
PIRVOLHV to ensure that the power requirements
are met.
Mounting and Connecting procedure
for Detector Separation
The PIRTB should be mounted to a solid, vibration-free
wall or post. The termination box should be electrically
connected to earth ground.
1. Lubricate the sensor threads with low vapor
pressure silicone grease, then install the sensor in
the conduit entry of the PIRTB. It should be tight to
ensure an explosion-proof installation, however, do
not overtighten.
2. Connect the PIRVOLHV wires to the terminal strip in
the PIRTB.
3. Connect the leadwires from the transmitter to the
appropriate terminals inside the PIRTB. Do not
ground the shield at the PIRTB. Ground the shield at
the transmitter end only.
4. Check the connections inside the PIRTB and place
the cover on the termination box.
5. Mount and wire the transmitter as described in the
instruction manual provided by the manufacturer.
CALIBRATE SWITCH
C2056
HOLD CALIBRATION MAGNET
AT OUTSIDE BASE OF TERMINATION
BOX AT THIS LOCATION
TO ACTIVATE CALIBRATION SWITCH
REMOTE LED
Figure 10—PIRTB Terminals and Calibration Switch
PIRTB
TERMINATION
BOX
SUITABLE WIRING.
MUST MEET ALL LOCAL CODES.
CONTROL DEVICE,
SUCH AS TRANSMITTER
PIRVOL
PROCESS MONITOR
D2030
Figure 11—Detector Separation