Page 9 - Issue 3 2023

NEWS

have changed the motor and still been still within our spec, but the new VFD was far more sensitive than the old one and it
stumbling around trying to find the detected the slight insulation breakdown and kept kicking out,” he adds.
problem. It’s a real testament to the
accuracy of these meters and the trust The wiring and the problem were solved.
we place in them every day,” he adds. • Fluke 87V DMM Industrial Multimeter delivers accurate frequency measurements
In a similar situation, Rob was able on adjustable speed drives, and captures intermittents as fast as 250 µS.
to find a subtle problem in a motor • Fluke Ti 480 Infrared Camera is a 640 x 480 thermal camera that is perfect for
lead with a Fluke Thermal imager. In professionals, with high-performance features, and increased sensitivity to visualize
this case, a VFD kept faulting out after temperature differences
technicians had upgraded the drive and • Fluke 754 Documenting Process Calibrator - calibrates critical safety
motor. “We checked the wiring with instrumentation on the tissue machines. “Each machine has a set of critical sensors.
the insulation tester and found a slight A couple of times a year we verify the calibration on the pressure transmitters for
degradation, but it was still within the those sensors with the 754 and the pressure modules,” says Rob.
acceptable threshold,” Rob explains. • Fluke 773 Milliamp Process Clamp Meter - determines whether a sensor is really
They changed the VFD, but the bad or whether the card is just not generating the 4 – 20 output. “You can put the
problem continued. They were just 773 on the PLC and it’ll tell you exactly what it is outputting, so you can tell whether
about to change the motor when Rob you’ve got a blown channel or if the instrument is shot,” Rob explains.
decided to bring out a Fluke infrared
camera. “We scanned the motor leads Contact Comtest, Phone 010 595-1821, sales@comtest.co.za, www.comtest.co.za
with the camera and the centre phase FACEBOOK: bit.ly/3iuk4cg
lead lit right up,” Rob recalls. YouTube: bit.ly/2V4nc6j
It turned out that technicians had LinkedIn: bit.ly/3rpTu86
left the old wiring when they upgraded Product: https://bit.ly/3OtdMZJ
the VFD and motor. “The insulation was HASHTAGS: #preventivemaintenance #Comtest #Fluke #thermalimaging

How a pressure sensor helps keep

boats from capsizing

cean going boats can be fitted with a canting keel (tiltable keel). The main
performance benefit of this tiltable keel is that, when the keel is tipped to
Othe side which is facing the wind (windward), the tilt of the boat is reduced.
In case of possible capsize, the boat can be righted again by tipping the keel to its
maximum extent. Since 2014, canting keels are mandatory in sailing races.
The keel is activated with the hydraulic cylinder built into the floor of the boat and
connected to the keel. The distributor is between the hydraulic group (electric motor,
hydraulic pump and oil tank) and the hydraulic cylinder. This contains electrical valves
needed for controlling the hydraulic pressure. The Keller sensor 21Y is also connected
to the distributor and measures the pressure of the keel cylinder.
The skipper can influence the system and keel directly with a control box, using
this to power the distributor or, to save energy, make the keel sink down using a
‘release’ button.
Keller’s 21Y sensor has an accuracy of ±0,5%FS, a total error band of 1,5%FS
@ -10 to 80°C, and a pressure range up to 1000 bar.

Contact Instrotech, Phone 010 595-1831, sales@instrotech.co.za
Follow us: Facebook | LinkedIn | YouTube
Product URL: https://bit.ly/3RrO8pX
Hashtags: #Keller #Instrotech #pressure #transmitter

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