3-4
3.2.4 Distance from Sensor
The maximum cable length between the sensor and the transmitter is 1000 ft (300 m).
Brooks supplies 4-wire cable to connect the sensor to the transmitter. The cable is fitted with a
Eurofast connector for connection to the sensor. Cable can be ordered in lengths ranging from 6.5 ft
(2 m) to 500 ft (150 m). For longer cable lengths, contact the factory.
3.2.5 Accessibility for Maintenance
Ensure that the transmitter is mounted in a location and orientation that will allow easy access to the
terminals and to the display (if your transmitter has a display).
3.3 Mounting the Transmitter
You can mount the transmitter in any orientation as long as the conduit and wiring openings do
not
point upward. For transmitter dimensions, see Figures A-1, A-2 and A-3.
See Figure 3-2 for a diagram of the mounting bracket supplied with the transmitter. Both pipe
mounting and wall mounting are shown. Ensure that the transmitter is mounted and oriented in a way
that will allow easy access to the terminals and to the display (if your transmitter has a display).
Example
The transmitter is mounted 350 feet from a DC power supply. If you want to use
16 AWG cable, calculate the required voltage at the DC power supply as follows:
Minimum Supply Voltage = 18V = (Cable Resistance x Cable Length x0.5A)
Minimum Supply Voltage = 18V + (0.0080 ohms/ft x 350 ft x 0.5A)
Minimum Supply Voltage = 19.4V
Condensation or excessive moisture entering the
transmitter could damage the transmitter and result
in measurement error or flowsensor failure.
To reduce the risk of measurement error or flowmeter
failure:
•
Ensure the integrity of gaskets and O-rings.
•
Grease the O-rings every time the transmitter housing
is opened and closed.
•
Do not mount the transmitter with the conduit openings
pointing upward.
•
Install drip legs on conduit or cable.
•
Seal the conduit openings.
•
Fully tighten the transmitter cover.
CAUTION
Instruction and Operation Manual
X-CM-QmBS-eng
Part Number: 541B052AHG
June, 2008
Section 3 Installing Field-Mount Transmitter
QmBS Sensor / QTA Transmitters
