Amazingly, some house don’t have a main disconnect. If such is the case, you can look at the meter to see how many amps it’s good for. Somewhere on the bottom half of the face will be a number such as 30A or 100A, listing its maximum capacity.
Assuming the point of asking potential clients about their electrical service is to identify folks trying to live a high-tech life on a 30-amp service with four fuses, you could ask more basic questions like: Fuses or circuit breakers? How many circuit breakers? What are the numbers (eg: amps) on the double-wide breakers?
Probably more useful from an underwriting standpoint is to find out if their wiring is copper or aluminum, and what brand their panel is. Some of the older ones (such as Federal Pacific) have lost their UL listings for being poorly made and won’t trip out ever if overloaded, and poorly-done aluminum wiring connected to a new 200-amp panel can be more dangerous than an old fusebox.
I’m assuming and hoping that an agent actually visits new clients to get accurate underwriting info.
Right, I wasn`t attempting to correct you. I was trying to back you up with via the NEC. I did read the previous posts and no-one mentioned the NEC or the 80% rule. Sorry if it came off otherwise.
Our underwriting guidelines (as well as many other companies) state that if a home’s electrical system has less than 100 amp service, we will not write the policy. We do ask if it uses breakers or fuses to help us determine amperage.
Suprisingly, ZB, many people do know their service rating. In many cases where older homes are insured, there may be an inspection to verify this.
Amp usage is irrelevant. Amp ratings are typically 60, 100,150, 200 amps available to the user (but the main breaker can only be loaded 80%). The restriction being the size of the feeder coming into the house from the transformer and the size of the main breaker that feeds the service. 240 is the typical voltage present between phases.
A house with breakers does not mean that the house has at least 100 amps. There are breaker panels that are rated at 60 amps with a 60 amp main breaker.
Crafter_Man - the NEC does not specify a limit of the combined cumulative ratings of the circuit breakers in the panel. In your case you could have a 200 amp panel with 1000 amps of cumulative breaker ratings and not be in violation. The only thing the code specifies is a 42 circuit limit and an 80% load on the main breaker. So in effect you can only load the service up to 160 amps continuous (for your 200 amp panel). Some larger homes will have 2-200 amp panels for the service giving them a 320 amp combined total load capability.
The post by Whuckfistle is exactly why I stated earlier on that the way to determine the supply to a dwelling, or any other consumer, is to look at the supply contract.
I does not matter is you have a 1zillion amp breaker, it does matter what power you are contracted for.
In the contract the supplier will state the agreed price per unit, often with additions for consumption above the agreed contract limit, but there will also be some statement in the contract that which will specify the maximum supply.
The maximum supply is always higher than the contract supply.
The contract supply might even have things in it such as short term peak demand penalties.
The distribution system in the dwelling, ie your fuse box-isolator etc, must be able to cope with maximum supply available continuosly and be able to disconnect the system under fault conditions.
So if you are contracted for a 100amp supply, then you could have a 200amp isolator and fusebox, however your protection device (the incming supply fuse) would still be rated at 100 amps.
This is why you cannot take as gospel the current rating that is moulded into the body of your isolator or fusebox as being your supply from your electricity company.
casdave, I’ve never heard of anything like that for residences in the US. I think some businesses have contracts set up like that, but I don’t really know that.
No matter who your supplier is, there will be a set of terms and conditions.
This will stipulate methods of payment, deadlines for payment, possibly who to call in the event of service failure, all that kind of stuff.
You may not have the contract in your house, but your supplier will only provide services under certain conditions and these have to be specified.
If you do not have the contract, then you will be able to contact your service provider and they are obliged to send you the correct paperwork.
Many domestic users are unaware that they have a contract, simply because they have not seen one, it does exist and will not be as complex as an industrial contract but you definately have one, it would be very difficult to sue for non-payment without one because the company has to prove that you agreed to pay for the service they provide.