I have inspected an electrical panel with the main breaker missing. I could not read the label on the entrance wires. The schematic on the panel reads that 75 amps max branch breakers be used. I think the house is supplied with 60 amps but I am not sure. The best way to describe the supply wires is they were the size of a small sharpy marker (not the big fat markers) or a chapstick tube. Thanks for any input anyone might have.
Aluminum or Copper. It sounds as if the conductors you are talking about may be 100+ but that does not matter if the panel is lower. Go with the lowest is the general rule. Need more info! The Guru’s should be along shortly!
Randy
I am assuming that this is a service due to your reference to the service conductors.
This needs to be deferred to a licensed electrical contractor
Would love to see a couple snap shots for good measure however!
I am curious as to what is meant by the “main breaker is missing”.
Could this be a split buss panel? These can be hard to decipher.
Are there any other labels in/on the panel? Usually it is stated somewhere on the label you saw.
Thats what I would think too, but in this case you cannot verify it without the other info.
I would tell the client to have it further investigated by the utility company or licenced electrician.
Where they in a pipe “service entrance raceway” or was there a cable like this one exposed on the side of building supplying the meter and fuse box?
this is a one example of this one of the breaeker box look like this http://www.inspect-ny.com/fpe/stlou022.gif
here the other one http://www.warreninspect.com/images/198.jpg
so there two of them it will give you a rough idea.
but if you can take a photo of the breaker box and show it to us we can able tell it from there
Merci, Marc
Usually in a new type service panel a 100, 125, or 200 amp breaker is present. This service panel had your typical 40 amp, 20 amp, 30 amp, and 50 amp breakers. There was no main breaker visible or labled but there was a closure cover missing so the wires and bus bar were visible. This would leave more then 6 throws.
How old is the home and what is the square footage? Is this an upgraded panel?
1986 and 1400 sq.ft
Still needing help on service amperage.
So it might be safe to assume that the service to the house might be 60 amp, but thats only going based on square footage and that would be the minimum service size.
Without more information from you (like pics, etc.), you may consider using the term “unknown” when listing the service amperage. 
This makes a BIG difference.
Definitely not a split buss then and most likely a 100A. Without more info I can’t help much more.