Is Panel Upgrade necessary?
To see if the panel upgrade is necessary, the total load of the panel should be known. If by adding new EV charger load , the total load does not exceed maximum panel capacity (Rating) then panel upgrade is not necessary. Otherwise, panel upgrade should be done first before adding new EV charger load to the panel.
Total load of the panel could be calculated by a qualified electrician using method explained in section 6 of OESC (Calculation method); however, there is a simpler way that could be used by home owner without doing complicated calculations.
How much the panel has free capacity?
Please contact Hydro/Utility company in the region your home is located and ask them to send you electricity consumption record for last two years. This is free service that hydro/utility companies offer to the home owners. You will get an excel table containing 720 rows for 720 days (two years) and 24 column in each day ( one record for each hour). Each cell in the table shows KWH consumption for one hour. Please find the highest KWH in the table and multiply it by 1000 to change KWH to WH and then divide it by 240 V to get maximum current consumption during last two years. Now, multiply it by 1.25 as safety margin for load growth. Please deduct resultant number from the Panel rating. What is remaining is the maximum available free capacity of your panel.
Example:
A home in Richmond Hill does have a 100 Amp panel. The two year electricity consumption records has received from ALECTRA utility and it shows that the highest electricity consumption is 6.34KWH and it happened on 23rd of June 2021 between 10:00 AM to 11:00 AM. Is it possible to add a Tesla Wall connector Gen3 for charging Tesla Model 3 standard range? Is a panel upgrade necessary?
Answer:
6.33 KWH x 1000 = 6,330 WH
6,330 WH / 240V = 26.38 Amp
26.38 x 1.25 = 32.97 Amp =~33 Amp
(Panel Rating) - (Calculated Max. Current) = 100 Amp - 33 Amp= 66 Amp.
So, spare panel capacity is 66 Amp.
TESLA wall connector Gen 3 could be set up to maximum of 48 Amp.
As the maximum current of the Tesla Gen3 charger (48Amp) is less than spare capacity of the panel, no panel upgrade required.
To see if the panel upgrade is necessary, the total load of the panel should be known. If by adding new EV charger load , the total load does not exceed maximum panel capacity (Rating) then panel upgrade is not necessary. Otherwise, panel upgrade should be done first before adding new EV charger load to the panel.
Total load of the panel could be calculated by a qualified electrician using method explained in section 6 of OESC (Calculation method); however, there is a simpler way that could be used by home owner without doing complicated calculations.
How much the panel has free capacity?
Please contact Hydro/Utility company in the region your home is located and ask them to send you electricity consumption record for last two years. This is free service that hydro/utility companies offer to the home owners. You will get an excel table containing 720 rows for 720 days (two years) and 24 column in each day ( one record for each hour). Each cell in the table shows KWH consumption for one hour. Please find the highest KWH in the table and multiply it by 1000 to change KWH to WH and then divide it by 240 V to get maximum current consumption during last two years. Now, multiply it by 1.25 as safety margin for load growth. Please deduct resultant number from the Panel rating. What is remaining is the maximum available free capacity of your panel.
Example:
A home in Richmond Hill does have a 100 Amp panel. The two year electricity consumption records has received from ALECTRA utility and it shows that the highest electricity consumption is 6.34KWH and it happened on 23rd of June 2021 between 10:00 AM to 11:00 AM. Is it possible to add a Tesla Wall connector Gen3 for charging Tesla Model 3 standard range? Is a panel upgrade necessary?
Answer:
6.33 KWH x 1000 = 6,330 WH
6,330 WH / 240V = 26.38 Amp
26.38 x 1.25 = 32.97 Amp =~33 Amp
(Panel Rating) - (Calculated Max. Current) = 100 Amp - 33 Amp= 66 Amp.
So, spare panel capacity is 66 Amp.
TESLA wall connector Gen 3 could be set up to maximum of 48 Amp.
As the maximum current of the Tesla Gen3 charger (48Amp) is less than spare capacity of the panel, no panel upgrade required.