I've never received advance notice of a power shutoff before and none of the line powered clocks in the house had lost time or reset so I figured the work had been deferred to the 31st. This turned out to be the case since the electricity went out right at 9:00 AM sharp yesterday morning. I decided to go to a restaurant and have breakfast and when I went outside, I got to see the hydro company doing their work a couple of houses down:
They were installing two new poles and a new distribution transformer.
This is the old Ferranti-Packard transformer being lowered to the ground. This transformer might be original to when the street was built in the early 1940s. I got to talk with one of the guys on the work crew and the new transformer has a larger kVA rating than the one they removed but the distribution voltage is still 4160. If it is the original transformer, the size has more to do with the core being designed to pass 25 Hz than any large kVA rating and the guy I was speaking with mentioned that transformer capacity was becoming an issue. Here, houses built in that era typically all had 60 amp services and the electricity distribution system would've been designed around that when it was built for the neighbourhood. Since then, with most houses being rewired with new 100 or 200 amp services, everything designed around all of houses having 60 amp services has become oversubscribed. Now that air conditioning is standard and things like electric car chargers etc. are becoming more common, I can see how current draws could be large enough at times to cause problems for the old infrastructure.
The hydro company did file plans with the Ontario Energy Board a few years ago that proposed replacing the existing distribution infrastructure so that the secondary voltage from the Hydro One interconnects was carried all the way to local pole mounted transformers to avoid having large neighbourhood substations and an extra step of conversion to an intermediate distribution voltage like the 4160 V in my neighbourhood. I don't know if that plan got cancelled though. Hopefully they aren't doing major infrastructure work only to have to replace it soon with another round of major infrastructure work.
Interestingly, the whole time I've lived here, the line voltage has always been a touch high, usually between 126-128 volts outside of peak air conditioning time. The new transformer's been set up to deliver a few volts less and the plug-in voltmeters now show around 124 volts instead.
