Multifamily dwelling 220.84 (back in the day)

[Tainted]

Back in the day in the 1900s, how was multifamily dwelling calculations performed? I usually work in really old apartment buildings and I'm wondering what demand factors were used before we had 220.84?

Also as a bonus, how was a single dwelling unit calculated?

Reason I ask is because there is an 1950s apartment building I went to which had 100 amp 3-phase feeders feeding 3 apartments each. No apartment had a dedicated main overcurrent device.

Can anybody give me some insight on this?

 

[tortuga]

In the 1951 code you would calculate your feeder based on section 2203 take your calculated load similar to today 3 VA per sqft.
There was only one kitchen appliance circuit that added 1500VA for each unit, no laundry or bathroom circuit.
Demand factors for general illumination were:
first 3000 Watts was at 100%
Next 117,000 watts at 35%
And over 120,000 watts at 25%

Motor, Range and Fixed Appliance would be calculated separately and added on.
There was a range demand table similar to today,
and four or more Fixed appliances could take a 75% demand factor.

 

[Tainted]

In the 1951 code you would calculate your feeder based on section 2203 take your calculated load similar to today 3 VA per sqft.
There was only one kitchen appliance circuit that added 1500VA for each unit, no laundry or bathroom circuit.
Demand factors for general illumination were:
first 3000 Watts was at 100%
Next 117,000 watts at 35%
And over 120,000 watts at 25%

Motor, Range and Fixed Appliance would be calculated separately and added on.
There was a range demand table similar to today,
and four or more Fixed appliances could take a 75% demand factor.

I tried looking everywhere online for that 1950s code in pdf lol. Very difficult to find. So basically they did not have anything like 220.84 where you do a bulk calculation?

Most old NYC apartments are 2-pole 60 amps.