Ferranti FD and FDb meters

In this video an old Ferranti FDb and a Ferranti FD are connected up to a 4 Ampères test load.
These meters are rated at 2½ Amps for 230 Volts 50 Hz.
Vintage would be from the early 1920's.
These meters were used on 750 Watt controlled hotwater loads
ex Whangarei, Northland, NZ.
These meters were given to me by a Nortpower inspector about 15 years ago

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