Multimeters for the Power Industry Technician/Relay Test Specialist
An ideal general-purpose multi-meter for the rigours of the power industry technician the APPA 70 series meters are all well configured for the rigours of the job. Being a tougher environment electrically, this series is very sensibly rated Cat 4, an excellent investment. Given the time the meters are used on the job, APPA has also spent a lot of time making them ergonomic to use with just one hand, plus being very nice indeed to hold. A rubber outer sleeve adds extra robustness but also includes useful features like a tilt stand, facility to hang the meter off a nail or hook at the substation panels, and convenient test lead storage. The APPA 77 incorporates a very useful True RMS function, and 10 amp current ranges. This makes it our most popular meter in this class.
Without doubt this meter is the most popular choice for the power industry professional! It is really built for the job, combining APPA’s famous ergonomic operation with a robust shock proof Cat 4 meter that is packed with relevant features. Naturally, accuracy of reading is correctly-specified at an impressive 0.08% basic DC V accuracy. Low impedance voltage detection is also combined with non-contact voltage detection for clear and unambiguous warnings of voltage actually being present in industrial situations. When it comes to industrial voltage and current readings in plant where non-symmetrical waveform distortion so often exists, normal True RMS meters have major errors but the APPA 99II has the “AC+DC True RMS” facility to allow accurate reading regardless! Its backlit 6000 count LCD offers excellent resolution and has a high resolution bar graph analogue display as well to aid assessment of rapidly-changing values. Naturally extra features like temperature, smart data hold, and fast peak hold all are included to make the APPA 99II a first rate choice.
For the advanced power parameter measurement at the upper end of the scale, or as a very handy meter for the relay testing technician, the Megger PMM-1 is a unique solution to many problems likely to beat most standard DMM’s in this environment.
More fully explained, the Power Mulitmeter (PMM-1) version 2.5 is a next generation multifunction instrument for measuring ac or dc voltage, ac primary and secondary current, power, reactive power, power factor, phase angle and frequency of a single or three-phase electrical system.
In the single-phase mode, the PMM-1 is easily configured to measure the amplitude and phase angle between any two voltages and current inputs. These measured quantities are then displayed in an enlarged font size for easier reading on a graphic display. In three-phase mode, all measured quantities are displayed simultaneously on a large, easy-to-read graphic display.
The unique firmware in the PMM-1, combined with a built-in, microprocessor-based timer, is specifically designed to ease testing and commissioning of protective relay systems, including induction unit pickup and timing tests. The internal timer responds to a variety of start and stop gates, including the application of ac or dc voltage, and opening or closing of dry contacts.