Old Electrical Equipment - Sangamo S29 electricity meter

Three phase, three wire kilowatt hour meter.

Exterior

Sangamo S29 kilowatt hour meter Sangamo S29 kilowatt hour meter This very large meter is a three phase, three wire model. Made by Sangamo Weston Ltd., model S29.

The meter is approximately 8 inches square (20cm), and 7 inches depth (18cm).

Exterior

Sangamo S29 back view Sangamo S29 back and side view Sangamo S29 wiring holesr The case is made from black bakelite, with two screws securing the front cover and another two for the wiring terminals cover.

One of the small spacers on the back has broken off.

There are six holes on the bottom edge for wiring - two holes for each phase. There is no neutral connection.

Front with and without cover

Sangamo S29 electricity meter with cover removed Sangamo S29 electricity meter The front cover has three windows for the register, rotating disc and information plate.

The six terminals along the lower edge each have two screws. Wires enter from below.

The two small L shaped pieces of metal are the connections for the potential (voltage) coils. Removing the screw from these isolates the coils from the main terminals, so that equipment can be connected for testing purposes.

Front plates and top

Front inside of the S29 meter Top inside of the S29 meter

Top dials

Sangamo S29 dial register Sangamo S29 dial register This shows a reading of 1 kWh.

As is common with this type of dial register, each pointer rotates in the opposite direction to the previous one.

Lower plate

Rating plate and terminals on a Sangamo S29 meter Rating plate on a Sangamo S29 meter Sangamo Weston Ltd., Enfield, Middx., Eng.
Model S29 Watthour Meter

3x10 Amps, 50 Periods, 3ph.3w.
3x400 Volts, 150 Revs / kWh
Form 2

No. T 17055

Potential coils

Sangamo S29 potential coil Sangamo S29 potential coil The potential (voltage) coils are contained in black cylindrical shells.

There are two coils, one on each side of the meter. Wiring is colour coded red and blue, for the red and blue phases respectively. The black wires connect to the yellow phase.

Current coils

Sangamo S29 current coil Sangamo S29 current coil There are two current coils, made from enamelled copper wire. These are of substantial thickness, since the full load current passes through them.

There are two coils, one for the red phase and one for blue. This meter has no neutral connection, so it is not necessary to have another coil for the yellow phase.

Upper mechanism

Sangamo S29 upper mechanism Sangamo S29 upper mechanism View from above, showing the rotating disc and laminated frame.

Side view of internals

Side internal view of a Sangamo S29 kilowatt hour meter Side internal view of a Sangamo S29 kilowatt hour meter Complete view of the internals from the left and right sides.

Covers

Bakelite S29 electricity meter covers Bakelite S29 electricity meter covers The front cover has three windows, which are covered with a single piece of glass.

Both covers are secured with two screws which have holes for sealing wire.

Wiring diagram

Sangamo S29 wiring diagram A small label showing the wiring diagram is fixed inside the terminal cover. RYB refers to Red, Yellow and Blue phases.

Brass gear wheels

Brass register mechanism, Sangamo S29 Another side view of the brass gear wheels behind the register pointers.

Video about this item

This meter is shown working with a phantom load arrangement. View this video on Youtube.

 

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