Polycarbonate housing having UL 94 V-0
All Rishabh meters are housed in robust case with classical finish. The case is made of polycarbonate, which is flame retardant and non-drip and confirms to international regulations UL 94 V-0. Polycarbonate is a very tough and light weight engineering plastic material which has got the best mechanical properties very close to a metallic housing. It is 10% glass filled, glass fibers give it extra toughness.
All Rishabh meters are fitted with scales which slide in guide slots and there is a window which click-fits into the housing after the scale is fitted or removed. This is the only meter in India which offers this interchangeable scale feature. The advantage is that it reduces the inventory of the stockists, panel builders as well as end users. The basic meters are accurate to 1% and the variation scale to scale is less than 0.5% giving a total accuracy of 1.5% max. The guide slots are very accurately designed such that the pointer cannot be damaged even by the most unskilled user. At the same time the window is such that it closes automatically if left open inadvertently when the meter is fitted in the panel. Out of the four directions in which the dial can be inserted, there is only one correct position in which the dial can be inserted. The dial has a small slot by which it can be pulled out easily either using nail or a tip of a pen or clip.
Knife edge Pointer
Pointer edge is a knife edge and is made of aluminium sheet of 0.05mm thickness. This makes it very light weight but at the same time, it is rigid by a specially designed V-profile. The sheet used is a pre-coated aluminium sheet so that the adhesion of the paint is very good. The pointer is fitted on to the cross arm by a special flapping process so that it can never disengage even in extreme temperature or presence of vibration or shock.
Terminal screws and clamps
Self lifting terminal screws are connected to the terminal clamps. Self lifted clamps gets lifted with the terminal screw while unscrewing, this simplifies clamping of the connectors or wire and save the time.
Terminal protection with click-fitting back cover
All Rishabh meters are supplied with a self-clicking back cover which covers the terminals. This is very important feature especially for the voltmeter because these meters are usually connected on the front panel which can be opened and can be hazardous for the engineer while the maintenance of the panel is being done. The self-click avoids problems of loosing the screws and washers.
The meter has a unique swivel clamp which could be mounted in any of the two different positions at 90 deg to each other. This makes the meter suitable for grid-racking so that a number of meters can be mounted horizontally or vertically in one rectangular cut-out. This feature is also useful because making one rectangular cut-out is more economical than making several cut-outs. The design of the housing and swivel is such that it can accommodate any panel thickness from 1mm to 40mm.
The maximum demand ammeters BM 48/72/96 & EB 72/96 monitor the most economic use of transformer stations & LT distribution feeders by indicating the thermal / time characteristics of the load. The high torque of the thermal movement drive a red slave pointer linked to the instrument pointer. The slave pointer will remain at the maximum value reached for a subsequent reading until being manually reset by a sealable reset knob to the position of the instrument pointer.
When the instantaneous and maximum demand currents are required, the EB 72/96 instrument, which combines a thermal bimetallic and a moving iron movement in the same case mounted diagonally opposite to each other. These meters are suitable for frequency range of 15-400Hz.