Fuse Boxes and there offspring

[Jim Reynolds]

I am in the process of preparing my wife's grandmohter's home so that it can be sold. The house is about 60 years old and has had little maintenance. We have completed all the major repairs except for one.....the Hot Water Heater. I am by no means an expert but I know that something is not right with the way that this heater is hooked up. This house is one of those homes where there was not enough fuses so a new fuse boxes were added as needed. In the laundry/furnace room there is a main fuse box and three other fuse boxes spliced off the main box. One of these is the fuse box that feeds the hot water heater and in it there are two fuses (the push button type). The hot water heater is very very old and keeps popping the 30amp fuse. The hot water heater leaks so I have decided to replace it. At first glance I thought this was a 120v hot water heater since there is only one cable ( 10-2 w/ground) coming out of the wall. (yes coming out of the wall, no junction boxes in this house, and the ground is clipped off). When I trace the wire back to the WH's fuse box, there is one black wire coming in to a fuse, and one white wire coming in to a fuse and nothing else. When I test the circuit I get 220v across the white and black ( only the fuse on the black wire pops). I have not opened the main box yet but I am pretty sure that someone spliced two 110v lines to get 220v. Has anyone seen anything like this before and what is the best thing to do ? It looks like the rigged the water heater also since there is a single red wire just hanging there.


Thanks,
JMR

JMR

[mrcaptainbob]

Well, they almost did it right. It does sound like a 220 unit. What should've been done was to wrap the white wire with red tape at both ends as a tell-tale that it was a hot line. You could still do that when you install the new unit. A 220 water heater only needs the voltage and the ground. (I just recently found that out on this forum!) So you should end up with the black wire on one side (110) and the red taped white wire on the other side (110). That tape can be gotten at any box store or hardware store in the electrical department. A couple of other points....verify that the wire isn't 14 gage, and also that the fuse panel can be seen from the water heater location.

[HayZee518]

Some water heaters can be wired for sequential or non sequential loads. Non sequential both elements pull in when heat is required, sequential, when calling for heat, the lower element is energized when cold is detected, then switches to the upper element. Usually the upper element is wired through an off peak meter connection (extra meter and timer supplied by the power company) Wire colors at the terminal box are black, red, yellow and blue.

[HayZee518]

You can just replace all the main service components with a 100 amp circuit breaker panel. Chances are the meter is inside now right next to or just above the main pull-outs. Meter will have to go outside. Feed for a 100 amp service is 2/3 aluminum SEU cable.
The old wiring - Knob and tube will need to go into a 4 inch square junction box, get spliced into romex, and go to the panelbox under an appropriately sized breaker.
Makes installing new equipement easier too! The water heater would need a two pole 30 breaker with #10/2 romex

[Jim Reynolds]

I think the safest thing to do is to replace the wireing between the main fuse panel, water heater fuse box and water heater. The existing wiring does not have a ground wire and I do not feel comfortable setting this up without one.

Thanks for all the help,
Jim Reynolds

JMR

[HayZee518]

I drew up what I can remember about old services that use knob and tube and the porcelain fuseholders. The meter was fastened to the service panel and had two wires in and out of the meter. The main came in via a 3/4" pipe and the ground looks like a 5/16" metal braid with a #8 solid copper within. This was just fastened to a lug inside the main pull out panel. The other end went to a cold water pipe with a clamp. The "neutral" went to a brass lug on the fuseholder and every other fuse was the neutral. The two outer feeds were the 220 between them. The main was either 35 amp cartdridge fuses or 30 amp screw in fuses. If you don't want to change the entrance then pick up a 30 amp, 240 volt fused disconnect and wire the way I have it shown. Feed it with #10 solid copper. The ground (bare) will go to the ground lug with the other end grounded to the green screw at the hot water heater. The black and white (red taped) will go to the heater input leads.