Intek RheoVac DR User Manual

Page 8

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Electronics Unit Site Selection

The RheoVac DR system may have up to three electronics enclosures; a main processor box, an
optional distribution box, and an optional transmitter box. These enclosures should be installed
in a convenient indoor location and should be kept away from direct sources of heat. The
maximum temperature rating of electronics is 120°F; ensure that this temperature will not be
exceeded inside the enclosure. Once the wiring connections are made, close and latch down the
box lid to protect the contents from damage and debris. The enclosures should be located in a
dry area and should be kept clamped shut during normal operation. Do not allow water to get
into the enclosures. If installed outdoors, build a roof over all enclosures to prevent potential
water infiltration, or direct sunlight to overheat contents.

A. Processor Enclosure: This 12x10 NEMA 4 enclosure houses the display and central

processing unit. Input power (100-250 Vac, 50/60 Hz) is connected inside this enclosure.
This enclosure should be installed in a convenient location and should be kept away from
direct sources of high heat, such as uninsulated steam lines.

B. Distribution Box (optional): This 8x6 NEMA 4 enclosure is typically located near the probe

that is closest to the processor enclosure unit. It is connected to the main processor with an
RS-485 bus DeviceNet™ cable, which can be hundreds of feet long. The probe and
transmitter RS-485 cable connections are also made within this box. The probe and
transmitter cable lengths should be 15 ft. or less.

C. Transmitter Box (optional): This 10x8 NEMA 4 enclosure contains terminals for accessing

the optional eight 4-20mA signals. It can be located in or near the control room so that the
4-20 wires do not have to be run from the plant floor. An RS-485 DeviceNet cable connects
the distribution box to the transmitter box. (There are restrictions on how this can be done,
so check manual SECTION 6, or contact the factory.)



!!WARNING!! The FTP probe and the RS probe(s) contain components and materials that
have a temperature rating limit of 210°F. If line and fluid temperatures are anticipated to exceed
this limit, the probe(s) must be removed from the vacuum pipe before and must not be reinstalled
until the problem condition has passed. Failure to do this can result in severe damage to the
sensor probe(s), especially when steam enters the vacuum pipe due to vacuum pump operating
anomalies. If Steam Jet Air Ejectors are used, always remove the RS probe from the line before

pump start up and do not reinstall the RS probe until stable operating conditions are achieved.

A. NPT/Hottap Installation

1. Check hardware. Verify that the probe slides easily through the NPT fitting or hottap

assembly and pipe penetration hole.

2. Verify there are the necessary minimum probe insertion clearance four (4) feet- between

pipe surface and any obstruction.

3. For NPT fitting installation, ensure that the threaded mating fittings (not provided) for

mounting the sensing probe(s) are installed at the proper locations in the process line.
Typically, 1" threaded couplings are needed for the FTP and the RS probes.