Material Type

Artifact

Other Name

CURRENT TRANSFORMER

Date Range From

1920

Date Range To

1929

Materials

METAL, LEATHER, PLASTIC

No. Pieces

1

Height

9

Length

22.1

Width

9.7

Description

CURRENT TRANSFORMER. OPEN SQUARE BALCK METAL PIECE WITH COPPER PIECES PROTRUDING FROM SIDES. PLATE READS, “CURRENT TRANSFORMER SERIAL NO. C62859 PRIM. AMPS 300, SEC. AMPS 5” SANGAMO COMPANY LIMITED”, “207435” AT SIDE OF PLATE. BROWN TAG ATTACHED TO TOP WITH STRING, TAG HAS BEEN CUT IN HALF.

Subjects

ELECTRICAL & MAGNETIC T&E

Historical Association

INDUSTRY

History

METERS WERE USED FOR RESIDENTIAL AND COMMERCIAL METERING IN THE CITY OF LETHBRIDGE. THIS METER WAS PREVIOUSLY ATTACHED TO A BOARD AND DISPLAYED WITH OTHERS IN A COLLECTION HIGHLIGHTING CITY ELECTRICAL DEPARTMENT HISTORY AT THE METER SHOP UNTIL 2009. ACCORDING TO METER SHOP DONOR GRANT FYFE “THE ROLE OF THE METER SHOP IS TO INSTALL THE METERS, REPAIR THE METERS.” “THESE METERS USED TO BE REPAIRED RIGHT IN THE SHOP. TODAY WE DON’T DO THAT, BUT WE SEND ALL THE METERS OUT FOR RECALIBRATION. UP UNTIL THE YEAR 2000, WE SERVICED ALL THESE METERS. WE STRIPPED THEM DOWN, CLEANED THEM, REPAIRED THEM AND RECALIBRATED THEM. THE GOVERNMENT WOULD COME IN AND CHECK OUR WORK AND SEAL IT.” METERS WITH MECHANIZED REVOLVING PARTS BEGAN BEING REPLACED WITH ENTIRELY DIGITAL MODELS IN THE YEAR 2000. ACCORDING TO AN INTERVIEW WITH RETIRED METER SHOP FORMAN WAYNE SCHELLHORN “WE ARE NO LONGER ABLE TO KEEP THESE METERS BECAUSE THERE IS NO MORE STORAGE ROOM.” FYFE SAID “WE WERE JUST LIKE WATCHMAKERS IN A WAY BECAUSE SOME OF THE JEWELS AND STUFF IN THESE METERS WERE VERY SENSITIVE, AND HAD TO BE CLEANED PROPERLY AND INSTALLED PROPERLY, OTHERWISE THE METER WOULDN’T REVOLVE PROPERLY AND IT WOULD SEIZE UP. IT WAS INTRICATE WORK.” THIS CURRENT TRANSFORMER DATES TO THE 1920S. ACCORDING TO FYFE “CURRENT TRANSFORMERS ARE USED WHEN WE HAVE A METER THAT’S RATED AT 5 OR 10 AMPS OR 20 AMPS AND WE HAVE A LOAD THAT’S GREATER THAN 20 AMPS. WE HAVE TO PUT IN A C.T. TO REDUCE THE CURRENT DOWN THE METER. SO WE PUT A PRIMARY WHICH WOULD BE RATED AT 5 AMPS, SO THAT JUST SCALES IT DOWN. SO IF YOU HAVE 300 AMPS FLOWING THROUGH THE LOAD, THEN YOU WOULD HAVE 5 AMPS AT THE METER, WHICH WOULD BE THE RATING OF THE METER, SO WE DIDN’T EXCEED THE RATING ON THE METER, THEN WE WOULD HAVE TO APPLY AND MULTIPLY IN THERE OF 60. SO WE READ THE METER AND THEN GO TIMES 60 TO ACCOUNT FOR THE ACTUAL COMSUMPTION.” SCHELLHORN ADDED “BECAUSE THERE’S NO SHORTING DEVICE ON THE SECONDARY SIDE OF THIS C.T. IT WAS DANGEROUS FOR A METER REPAIR MAN OR UTILITY WORKER TO WORK ON WHILE IT WAS HOT. IF YOU OPENED THE CIRCUIT UNDER THE SECONDARY YOU’D GET A VOLTAGE BUILD UP AND IT COULD GET UP TO HUNDREDS OR EVEN THOUSANDS OF VOLTS IN NO TIME AT ALL.” FOR MORE INFORMATION, PLEASE SEE PERMANENT FILE.

Catalogue Number

P20100046003

Acquisition Date

2010-09

Collection

Museum

Less detail