Analog Panel Meters:
Providence General Services is serving various Panel builders and contractors to supply various panel meters from variety of brands. Mainly we deal with two brands, CEWE and H Plus for Analog Panel Meters.
Panel instruments manufactured by Cewe Instrument are CE marked and produced in accordance to stated standards above. The electrical indicating instruments produced by Cewe Instrument comply with specifications IEC 60051, DIN 43802, DIN 43700, IEC 50081-1, IEC 50082-1, IEC 50081-2, IEC 50082-2, IEC 61010-1.
Accuracy of Analog Meters ranges from 1.5 to 3.
Operating Temperature range of offered Analog Panel Meters is between –25ºC and +50ºC.
The movements have pivot bearings, with highly polished pivots of hardened steel and sapphire bearings.
Cewe Instrument’s instruments are well (magnetically) shielded and it is not necessary to state in which type of panel the meters will be mounted. In cubicles the moving iron instruments can be mounted in high magnetic fields. Our instruments are designed for these conditions.
Most instruments are fitted with a zero (adjustment)-setting knob, by which the zero position of the pointer can be adjusted.
Removable Scales, with the Quadrant or the Circular Scale.
To prevent unintentional contacts with the instrument terminals protective covers are available as an accessory for instruments with front flange dimensions 48 x 48, 72 x 72 and 96 x 96 mm. The cover is snapped onto the rear of the instrument after mounting and connecting the instrument leads.
Standard instruments are made according to IP 54. Rubber gasket to seal against panel can be obtained as an accessory.
High relative humidity and corrosive environments in general to provide better environmental protection, require good component quality and surface finish.
Relative humidity max 95% for max 30 days per year. Otherwise max 85% Year average max 75%
The instruments are mounted with a snap-in mounting device as shown in the figure. This is a simple, reliable, and very time-saving method for mounting. There are no small screws or spring-clips to get lost.
Type of Analog Panel Meters:
Moving Iron Instruments:
The moving iron instruments have a silicone damping system. The screw containing the sapphire of the bearing is filled with silicone oil and the spindle is thus damped in its movement. Measures are taken that the silicone oil cannot creep out of the screw. The oil viscosity temperature coefficient is low and damping properties almost constant within the whole temperature range –25º – + 50ºC. By varying the viscosity of the oil, the damping properties can be chosen after application. Cewe Instruments moving iron instruments are characterized by low power consumption, high torque (low effect on friction) and a linear scale from approx. 20% of the measuring range.
Moving coil instruments:
Moving coil instruments are used for measurement of DC current and DC voltage. The movements have low power consumption and an approximately linear scale. Provided with a rectifier, the moving-coil instruments can be used for the measurement of sinusoidal AC current and AC voltage. In this case, the movement is average sensing, but the scale is graduated in r.m.s. The moving coil rectifier instrument is used where there are requirements for low power consumption (a linear scale from zero) or for measurements at high or varying frequencies.
Maximum Demand Ammeters:
Maximum demand ammeters with bimetal movements are used or the supervision of thermal load in transformers cables, motors etc. The thermal lag for the bimetal system is 15 minutes. The torque of the meter movement is great and its black pointer can move a red slave pointer, the position of which indicates the highest average value of the current. The slave pointer can be returned to the position of the black pointer with a special re-set knob. Maximum demand ammeters are also available in combination with a moving iron ammeter.
The pointer frequency meter is fitted with a transducer combined with a moving coil movement, can be chosen with front flange dimensions 72 x 72 mm and 96 x 96 mm. If other sizes and designs are required, we recommend moving coil instruments in combination with Cewe Instrument’s measuring transducers, e g DF 125/127.
Power & Power Factor Meters:
Cewe Instruments watt, var and power factor meters incorporate a transducer feeding a moving coil meter. This produces a very solid and vibration proof instrument.