PT-2 Three Phase Electromechanical Watt-Hour Meter

General Introduction
The three phase four-wire electromechanical watt-hour meter is designed to meet the latest IEC 60521 and BS EN60521 standards for measuring active energy in three-phase four-wire alternating current power grids. Connection is direct or by instrument transformers. The average service life (MTTF) of the meter is 15 years and the maximal overload capacity is 400%Ib

Components

1. Meter case
The meter case meets the protection requirements set by IP52 of IEC 60529. The series types of cases and terminal covers are available.

2. Terminals
The connection terminals are made of nickel-plated brass with features of high mechanical strength, good conductivity and corrosion-resistance.

3. Terminal block
For meter of steel or PC base, the terminal block is molded of heat-and flame-resistant bakelite. The voltage test link can be located inside or outside of the meter case.

4. Driving system
It has three electromagnet elements. Each element consists of a voltage element and a current element, all of which are mounted on the meter frame with two screws. Voltage coil is enwrapped in a thermoplastic case to ensure fine insulation. In addition, the voltage element has a low load adjustment mechanism.
The current element employs a simple and reliable load curve compensation mechanism to ensure the flat characteristic curve. An inductive load adjustment mechanism is on it.

5. Rotor
The rotor disk is made of a hard and high purity aluminum. The rotor shaft is turned of high strength brass. There is a small hole on the upper end for storing lubrication and for fitting a brass bearing. The lower end is cone-shaped to ensure fine guiding of the rotor.

6. Braking element
The magnet cube is made of AINiCo5 alloy and designed as U-shaped so that the effect of short-time over currents upon the magnet is negligible. A temperature compensation plate made of a special alloy, is mounted outside of the magnet. The error of full load can be controlled precisely by turning the adjustment mechanism.

7. Frame
The frame is die-casted by high quality aluminum-silicon alloy of stable property to avoid distortion. The application of static spray-painting on the surface prevents the frame from oxidation.

8. Upper bearing
The guide pin is made of abrasion-proof stainless steel, and embedded into the brass sleeve.

9. Lower bearing
Both double jewel bearing and magnetic bearing are available.

10. Register
The cyclometer type register consists of six drums. The kWh can be read directly. The drum is made of polycarbonate. The framework is made of hard aluminum alloy and can be manually adjusted and fixed with two screws to insure the proper mesh with the worm on the rotor shaft.

Technical Data

Typical connections diagrams

Outline & Installation Size

Three Phase Electromechanical Watt-Hour Meter