I live in a brownstone with 8 studio apartments. Many have two people living in them, so we could potentially have 16 people total. Our electrical system is out of date — 100 amp service for the building. Most of us don’t have A/C because of fear of overloading the system. Our grand plan is to upgrade the service from ConEd, run new lines up to each apartment, and install breakers to replace fuses in each apartment. I have a couple of questions for anyone who can help:
1. What is the appropriate upgrade to the supply? One electrician suggested a “200A single phase 220V main service switch” (which confuses me, because I thought single phase service came as 240, not 220V), while an engineer suggested 400A three phase — which I assume would be 208/120V for a building our size. Anybody care to comment?
(and)
2. Is it safe to split up the process — to upgrade the electric supply to even 400A, replace the main disconnect, but wait a few years to run the wires up to the apartments? We’re hesitant to spend the money to rip out the walls to replace the wiring up the building right now — but on the other hand the box for the main disconnect and the supply line from the street are rusting — so we’d like to address that soon.
All advice is most welcome. Thanks.
The loss thru wires may be measurable but hardly a concern. For one thing, the 400A wire is only from outside to your box only, a short distance. All internal wiring is the same.
Anon 2:08,
I wasn’t assuming that the electrician was trying to scam the original poster, just telling
the poster that the figures could be verified fairly easily. I should have added that if your electrician is more conservative by say 30% than the code, go with the electrician. If it’s off by more than that don’t assume they are dishonest, but ask them to explain their calculations, maybe you missed something, or maybe they didn’t do them and should have.
Apparently, the poster didn’t need the advice since s/he is an EE and probably did his own estimate. The NYC NEC does assume a 100% power factor for some circuits, and I still think it is a good starting point for the average brownstoner to verify their electrician is being honest about requirements.
Original poster here: I am also an EE so I do
know that you don’t just simply add together
the maximum amperage/appliance/A/C. There are
going to be 4 individual condensers (& heaters)
each with air handlers, humidifiers, purifiers.
It is a full gut. Your usual big-ass washer
& dryer & large refrigerator, multiple TVs,
computers, lighting for 4 floors. Just doing
on-the-fly calculations, I know 200 amps
is not enough. I just want to know what a ball
park cost for all this would be.
Daniel,
You might be an EE, but the practical side of the work should be left for the licensed labor.
Con Ed always asks us to add all the major heating and cooling amps in a building, as well as the appliances, when they conclude the amperage.
Though, I may know very little about the original posters circumstance, I can relate because there have been many customers that have called me to upgrade their current amperage because they want to add air handler units and condensers and they try to avoid any possible surge.
If the original poster can please provide us with more detail we can further assist her, but you should always design for future circumstances when considering this task. Especially if you’re:
a- gutting your home or,
b- building from scratch.
Scam or no scam, if there’s labor involved, someone has to be paid. If someone is providing a service for free, please post their name and number, or better yet don’t because that would be a scam
Anon, you may want to do the load calculation yourself. It’s not very complicated, but you can’t just add the amps at each outlet, you need to account for the load (the chances of every circuit being fully loaded at once are zero, the NEC has suggested % for different usage profiles.)
You can get a copy of the NYC version of the NEC for about $130. This will let you verify the electrician isn’t trying to scam you.
I’m an EE not an electrician, so unfortunately I don’t have any idea about the cost. ConEd can probably give you an estimate for upgrading the service, then double that for any required upgrades to the breaker box, etc. This is separate from the cost of upgrading the wiring, but I’m assuming anon 3:50 pm is including that cost.
Bkln Electrician here,
Are your units window type or individual condensers with air handling units?
The former is ok with 200 amps, but the latter will need 15-20 amps for each piece. In other words, a carrier type airhandler unit requires 15-20 amps dedicated alone. The condenser requires an additional 15-20 amps.
Will there be other attachments, such as humdifiers, air purifiers, etc.
Is this a typical brownstone or other type of building? Are you placing the units individually per floor for four seperate zones? For four seperate units?
Let’s talk about the other appliances. Are they large pieces (Sub-zero), will you have washer/ dryer(s)?
All these are major factors in determining the amps. And I’d say you need no more than 300amps, but the cost is insignificant from 300 amps to 400 amps.
As far as your question of contact, I can post my information, but are you under contract with anyone (GC, Electrician)? Under contract law, I cannot get involved. What you need to do is hire an architect or engineer. Or have Con Ed make the decision. Chances are, they’ll push for the higher amperage.
I’d like to help, but in my business, I’m a sub and I respect contracts (If one exist) between you and the other tradesman.
I live in a brownstone with 8 studio apartments. Many have two people living in them, so we could potentially have 16 people total. Our electrical system is out of date — 100 amp service for the building. Most of us don’t have A/C because of fear of overloading the system. Our grand plan is to upgrade the service from ConEd, run new lines up to each apartment, and install breakers to replace fuses in each apartment. I have a couple of questions for anyone who can help:
1. What is the appropriate upgrade to the supply? One electrician suggested a “200A single phase 220V main service switch” (which confuses me, because I thought single phase service came as 240, not 220V), while an engineer suggested 400A three phase — which I assume would be 208/120V for a building our size. Anybody care to comment?
(and)
2. Is it safe to split up the process — to upgrade the electric supply to even 400A, replace the main disconnect, but wait a few years to run the wires up to the apartments? We’re hesitant to spend the money to rip out the walls to replace the wiring up the building right now — but on the other hand the box for the main disconnect and the supply line from the street are rusting — so we’d like to address that soon.
All advice is most welcome. Thanks.
The loss thru wires may be measurable but hardly a concern. For one thing, the 400A wire is only from outside to your box only, a short distance. All internal wiring is the same.
Good straw man, though. Or is a nit-pick?
anon 10:12 am,
Installing the thicker wire that 400 amp service will require will waste less electricity than the thinner wire 200 amp service requires.
Please see “An Incovenient Truth”. Maybe 200 amps will suffice after that.
Anon 2:08,
I wasn’t assuming that the electrician was trying to scam the original poster, just telling
the poster that the figures could be verified fairly easily. I should have added that if your electrician is more conservative by say 30% than the code, go with the electrician. If it’s off by more than that don’t assume they are dishonest, but ask them to explain their calculations, maybe you missed something, or maybe they didn’t do them and should have.
Apparently, the poster didn’t need the advice since s/he is an EE and probably did his own estimate. The NYC NEC does assume a 100% power factor for some circuits, and I still think it is a good starting point for the average brownstoner to verify their electrician is being honest about requirements.
Original poster here: I am also an EE so I do
know that you don’t just simply add together
the maximum amperage/appliance/A/C. There are
going to be 4 individual condensers (& heaters)
each with air handlers, humidifiers, purifiers.
It is a full gut. Your usual big-ass washer
& dryer & large refrigerator, multiple TVs,
computers, lighting for 4 floors. Just doing
on-the-fly calculations, I know 200 amps
is not enough. I just want to know what a ball
park cost for all this would be.
Daniel,
You might be an EE, but the practical side of the work should be left for the licensed labor.
Con Ed always asks us to add all the major heating and cooling amps in a building, as well as the appliances, when they conclude the amperage.
Though, I may know very little about the original posters circumstance, I can relate because there have been many customers that have called me to upgrade their current amperage because they want to add air handler units and condensers and they try to avoid any possible surge.
If the original poster can please provide us with more detail we can further assist her, but you should always design for future circumstances when considering this task. Especially if you’re:
a- gutting your home or,
b- building from scratch.
Scam or no scam, if there’s labor involved, someone has to be paid. If someone is providing a service for free, please post their name and number, or better yet don’t because that would be a scam
Anon, you may want to do the load calculation yourself. It’s not very complicated, but you can’t just add the amps at each outlet, you need to account for the load (the chances of every circuit being fully loaded at once are zero, the NEC has suggested % for different usage profiles.)
You can get a copy of the NYC version of the NEC for about $130. This will let you verify the electrician isn’t trying to scam you.
I’m an EE not an electrician, so unfortunately I don’t have any idea about the cost. ConEd can probably give you an estimate for upgrading the service, then double that for any required upgrades to the breaker box, etc. This is separate from the cost of upgrading the wiring, but I’m assuming anon 3:50 pm is including that cost.
Bkln Electrician here,
Are your units window type or individual condensers with air handling units?
The former is ok with 200 amps, but the latter will need 15-20 amps for each piece. In other words, a carrier type airhandler unit requires 15-20 amps dedicated alone. The condenser requires an additional 15-20 amps.
Will there be other attachments, such as humdifiers, air purifiers, etc.
Is this a typical brownstone or other type of building? Are you placing the units individually per floor for four seperate zones? For four seperate units?
Let’s talk about the other appliances. Are they large pieces (Sub-zero), will you have washer/ dryer(s)?
All these are major factors in determining the amps. And I’d say you need no more than 300amps, but the cost is insignificant from 300 amps to 400 amps.
As far as your question of contact, I can post my information, but are you under contract with anyone (GC, Electrician)? Under contract law, I cannot get involved. What you need to do is hire an architect or engineer. Or have Con Ed make the decision. Chances are, they’ll push for the higher amperage.
I’d like to help, but in my business, I’m a sub and I respect contracts (If one exist) between you and the other tradesman.