Set #3 of Questions & answers on how to install, inspect, & troubleshoot building electrical systems, appliances, components.

This article series provides detailed inspection, troubleshooting, & repair information for building electrical systems and equipment including electrical service entry, electrical wiring, appliances, motors, receptacles, switches, lights, etc.

Building Electrical System FAQs-3

These questions & answers about building electrical systems, wiring, & components were posted originally at ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR - home - be sure to see the suggestions at that page.

On 2018-01-28 by Lawrence R Pelfrey

How do I find a junction box in a doublewide

On 2018-01-18 by (mod) -

Cynthia

In modern homes usually a kitchen will use separate circuits for receptacles and lighting and fans. It's a bit funny that one lower floor receptaclee is on that circuit but often that happens when someone adds a light or adds a receptacle where needed, by tapping into an existing lighting or electrical receptacle circuit that happens to have an electrical box near the spot where the new device isneeded.

Check there to see if it's a GFCI that has tripped.

If not, your electrician will start at the panel and follow the circuit looking for an open wire.

On 2018-01-18 by Cynthia

I hope someone can help me with this one! One of my electric circuits is not working and I am not sure how to find which outlet or wired light/ceiling fan that is causing the problem.

I do not have function of power to my kitchen light over the sink, the ceiling fan/light in the kitchen, the outlet to my exhaust fan also in the kitchen, and a downstairs outlet.

However an outlet that is connected to the light over my kitchen sink still works.

How is this possible since the light switch and outlet are wired right in the same box? Could someone please give me some info on how to go about finding the problem and correcting it?

On 2018-01-08 by (mod) - i took a pull apart electrical outlet

Linda

You posted this question also at, and we replied at

https://inspectapedia.com/Manufactured_Homes/Mobile-Home-Electrical-System-FAQs.php#FAQ

On 2018-01-08 by linda

i took a pull apart electrical outlet apart to remove so old paneling, two wires came out of outlet. Ho w do i rewire the two wires that pulled out of the plug in?

On 2017-12-05 by Kris

I want to drill the floor joists with a 1-1/2 " hole for home runs back to panel. How many #12-2 wires can I put in this size hole?

On 2017-11-23 by (mod) -

Anon

See FAN WONT STOP - LIMIT SWITCH at https://inspectapedia.com/heat/Furnace_Fan_Wont_Stop.php
and
see FAN WONT STOP - THERMOSTAT SWITCH at https://inspectapedia.com/heat/Thermostat_Switch_Settings.php#FanStuckOn

since one of those two sets of diagnostics will help you figure out why your heating system fan will not shut down as well as how to repair the problem.

On 2017-10-31 by Anonymous

Electric fan myth for a standard single family home air handler will not shut down checked alll obvious connections Fr’s cool relays it just will not stop short of turning off maimed

On 2017-10-19 by Billy

I have a house that is 50 years old. It has all 2 prong outlets. Do they have to be changed by code?

On 2017-10-14 by (mod) -

Steve,

It sounds indeed as if a larger gang box is what's needed: perhaps in fact the present box is so overcrowded as to both violate the electrical code and actually be so jammed as to invite continued problems.

But with all switches off when a breaker trips for that circuit we're told that there is a short to neutral or short to ground somewhere on the circuit. The short could be wire to wire or wire to metal box if the box is also grounded.

If I were debugging this I would pull off all of the switches, pull out and straighten the wires, inspect, label, then disconnect the connections, inspecting for damage, with some testing on each wire before restoring the work in a new larger box.

On 2017-10-13 by Steve

Dining room circuit has 3 switches that control chandelier, 2 wall sconces, 2 accent mini hi hats.

The switches jumble of ground wires in the box, occasionally touch a switches hot lead, tripping the breaker. Solution I’d to open the box, extend the switches to separate / isolate those growing wires that sleepwalk.

Works just fine until the last time it happened. I separated the wires, tested each switch for failure, continuity and short circuits,all fine. With all switches off, circuit breaker sparks and flips off every time I try to reset it. Is the breaker bad? Other possible causes? Thanks.

On 2017-09-15 by (mod) -

Leroy

I speculate that the fan is on the same circuit as the GFCI protected receptacle by your bathroom sink AND that the fan or its wiring or most-likely the switch (since you say this happens when you turn the fan OFF) is shorted or defective.

On 2017-09-15 by Leroy

When I turn off fan in bathroom gf on sink trips.

On 2017-08-23 by (mod) -

Joy,

I apologize for having to give an answer that means some work on your part, but if I am guessing correctly that your inspector found a Zinsco-Sylvania electrical panel in your home, your "inspector" was wrong. There has been no Zinsco electrical panel nor Sylvania-Zinsco panel recall from the manufacturer.

However the inspector is correct to warn you that the panel may be unsafe. It's common practice to recommend that the panels should be replaced.

A description of the problems with these electrical panels is at ZINSCO SYLVANIA ELECTRICAL PANELS - home https://inspectapedia.com/electric/Zinsco_Electrical_Panels.php
where you'll find a recommendation for replacement.

To replace the electrical panel you'd hire a licensed electrician. You might want to also see HOW SHOULD ZINSCO PANELS be REPAIRED: REPLACEMENT ALTERNATIVES at https://inspectapedia.com/electric/Zinsco_Electrical_Panels.php#Rep

On 2017-08-22 by Joy

I have a home built I. 1983 that had an inspection done on it. The inspector stated that the Sylvania electrical box was recalled. What is my next step?

On 2017-07-30 by Gary

In the 1970's ; the black wire is still hot, and the white wire was common (ground) Would I be correct on assuming this ???

On 2017-06-22 by (mod) -

You can use the website search box just above to find

TRACE ELECTRICAL CIRCUITS

On 2017-06-22 by Lisa

1990 mobile home. Fuse box shows 30a 2 pole breaker for dishwasher, only no dishwasher.

Original owners, original. panel. Fuse has wires running...? Checked where a dw might go, no outlet or junction box..? How do i find where wire goes save going under,...it's 100 here in ga

On 2017-06-16 by Ellie

Does the Main braker model HD4033 MOD. @ 400 Amp 240 V.A. C. 3 pole, has any recall from Sylvania?

On 2017-06-03 by (mod) -

Bobby,

And a tech note about why some comments don't post immediately: sorry that our comments box software blocked your earlier comment. When it sees a . in the middle of text it thinks it's a dangerous link. "... house.at ... " for example. On review I can of course unblock the remark as I've done below.

About grandfathering:

Generally any new electrical work must be done to current codes; in some jurisdictions working on an old circuit, such as remodeling a bathroom, will also prompt a requirement to add what's currently required - such as GFCI.

That buried box really must be made accessible, grandfathered or not: both so that future owners or electricians won't kill themselves trying to find a connector that's gone bad but that is totally hidden, and of course for safety or to permit future work. Even though it may be a pain, if I come across such a box I find a way to give access to its cover.

You can bring the box front out to a finished wall surface using a metal or approved plastic cover and you can even paint it. If there were paneling I'd still provide an access opening.


This U.S. NEC paragraph is quoted by Minnesota's guide for electrical wiring projects:

NEC 314.29 Junction boxes shall be accessible without removing any part of the building.

This document might be useful to you,

https://inspectapedia.com/electric/Minnesota-electrical-inspection-checklist.pdf

On 2017-06-03 by bobbylgorden

I have a question about grandfather laws. I have house built in 1958 which originally was a 1 BR house. There was a 2 BR addition added and the original BR became the Living room. I am doing some remodeling and was going to add a 6 outlet box about 4 foot off the floor for my entertainment center.

It is just my luck the right at the top of my hole for the 6 way box, is a box. Now, I don't know if it is a junction box or the old service panel. I have not uncovered it.

There is 110v and 220v wiring and they are live connections. My question is, can I uncover the "box" and not have to make an access panel on my LR wall, an access cover would be unsightly, and recover it with sheetrock or will I have to uncover it and bring it up to code.

I am pretty sure that here in MN, all junction boxes and service panels must be fully accessible but I don't know about grandfather clauses. Thanks for any insight you can give me.

On 2017-06-03 by (mod) re: grandfathering electrical work in Minnesota & Accessibility of Electrical Junction Boxes

Bobby,

And a tech note about why some comments don't post immediately: sorry that our comments box software blocked your earlier comment. When it sees a . in the middle of text it thinks it's a dangerous link. "... house.at ... " for example. On review I can of course unblock the remark as I've done below.

About grandfathering:

Generally any new electrical work must be done to current codes; in some jurisdictions working on an old circuit, such as remodeling a bathroom, will also prompt a requirement to add what's currently required - such as GFCI.

That buried box really must be made accessible, grandfathered or not: both so that future owners or electricians won't kill themselves trying to find a connector that's gone bad but that is totally hidden, and of course for safety or to permit future work. Even though it may be a pain, if I come across such a box I find a way to give access to its cover.

You can bring the box front out to a finished wall surface using a metal or approved plastic cover and you can even paint it. If there were paneling I'd still provide an access opening.

This U.S. NEC paragraph is quoted by Minnesota's guide for electrical wiring projects:

NEC 314.29 Junction boxes shall be accessible without removing any part of the building.

This Minnesota electrical inspection checklist might be useful to you,

• ELECTRICAL INSPECTION CHECKLIST, MINNESOTA [PDF], Minnesota Department of Labor & Industry, retrieved 2017/06/03, original source: https://www.dli.mn.gov/ccld/PDF/eli_inspection_checklist2.pdf

On 2017-06-03 by bobbylgorden

I have a question about grandfather laws. I have house built in 1958 which originally was a 1 BR house. There was a 2 BR addition added and the original BR became the Living room. I am doing some remodeling and was going to add a 6 outlet box about 4 foot off the floor for my entertainment center. It is just my luck the right at the top of my hole for the 6 way box, is a box. Now, I don't know if it is a junction box or the old service panel. I have not uncovered it.

There is 110v and 220v wiring and they are live connections.

My question is, can I uncover the "box" and not have to make an access panel on my LR wall, an access cover would be unsightly, and recover it with sheetrock or will I have to uncover it and bring it up to code. I am pretty sure that here in MN, all junction boxes and service panels must be fully accessible but I don't know about grandfather clauses. Thanks for any insight you can give me.

I am doing a slight modification to my home. It was a 1 BR and had a @BR addition. The old bedroom is now the living room. I wanted to add an additional outlet on the living room wall. I know how to wire outlets and understand home wiring.

While doing my project I found a junction box in the old part of the house.At the moment, I can only see the bottom of this mysterious box in the wall. I suspect it is the old service box as it appears to have 110v and 220v wires running into the box. I am in Minnesota and do not know if I must "uncover this box". I always thought any enclosure must be readily accessible. I am afraid to uncover it as it might be "grandfathered in" and if i uncover it, I will have to create and access in the middle of my living room wall which would be very unsightly.

On 2017-05-06 by (mod) re: how much does it cost to add an electrical circuit or to add a ground wire

Running:

The answer to a question about the cost of electrical wiring depends on

- where you live, as prices vary by country, province, state, city

- ease of access to a wiring path: e.g. access via a basement or crawl makes running circuit wires easy while running wires in a home built on slab where there is no access to a wiring path requires

wall cuts, snaking wires, more time and labor

- distances

- probably cost to replace existing wires as just adding a third external grounding conductor may not be acceptable by local building codes

- number of circuits requiring the repair

But we can put some bounds on the question: to wire a typical North American new home (meaning it's easy to run the wires as walls are not enclosed) is in the $10,000 range. Electricians typically charge $75 to $125/hour.

A single small job like running one circuit that's accessible is probably under $500. U.S. while cutting into walls or ceilings and snaking wires to re-wire an existing circuit to add grounding conductor and thus to replace all of the receptacles, could easily be twice that.

On 2017-05-06 by Running ground wire to main panel

How much would it cost to run ground wiring from bath and kitchen to main panel house is about 1300 sft ranch.

On 2017-05-05 by (mod) re: what to do if some electrical circuits are not working

Eric

To avoid a fire or death by electric shock I would leave the bad circuit OFF until you can get an electrician to find the problem and fix it. Typically she will find an open wire connection at a switch, wire splice, or light fixture.

On 2017-05-05 by Eric

I have no lights in one bedroom and one bathroom of my mobile home, the electrical outlets still work though in both rooms. What could be the problem?

On 2017-05-03 by (mod) re: can I use 220 wire to power a singlewide mobile home?

Sherrie I'm scared to answer you because a mistake here can kill you or burn the place down. So I have to give a generalized arm-waving reply before I duck:

Generally 220 Volts at a residential property is made up of two 110 volt service entry wires and neutral and ground wires from the electrical company.

That power source can, properly connected through a main disconnect switch to a main electrical service panel, can then deliver power to both 220V and 110V (or 240V 120V) household circuits through individual circuit breakers and wires in the building.

NONE of what I said has addressed the question of wire size - gauge or thickness, number of circuits in the home, location of panels, etc. Be sure you get help from a licensed electrician.

On 2017-05-03 by Sherrie

Can you use a 220 wire to power a single wide mobile home?

On 2017-04-12 by (mod) re: electrical damage after a lightning strike or thunderstorm

Melaney,

Because a nearby lightning strike can damage electrical equipment and leave it unsafe, risking a fire or shock injury, if it were my home I'd call a licensed electrician to ask for help.

A reasonable step to check individual circuits is to turn the circuit breaker to a fully off position, then back on. Sometimes it's not obvious that a breaker has tripped. But more likely there was lightning damage to the electrical feeders to the home or to its electrical equipment.

BE SURE to leave any odd-acting circuits OFF - such as flickering lights.

BE SURE that you have properly-located, installed, and tested smoke detectors working in your home.

On 2017-04-11 by Melaney

Last night we had a severe thunderstorm. There was a lightening strike very near by. The electricity remained on except in the master bedroom and ensuite. There were no switches to thrown to indicate where the problem might be.

What can I do to get the electricity back on in those rooms. I am on a limited budget and would rather not have to call in an electrician if at all possible. The diagram in the junction box is not helpful.

On 2017-03-25 by (mod) re: how do I send a photo showing how to jump the white wire to the ground screw to make a receptacle work

Mike

You are welcome to use the page top or bottom CONTACT link to find our email to send along a photo for comment.

Our Comments Box software, for security reasons, doesn't let readers include files nor photos.

Watch out: The danger of connecting neutral to ground anywhere but in the panel is that when the circuit is active current is flowing on the grounding conductor or for BX/armored cable it's flowing in the metal BX jacket.

Those are not intended to carry normal operating current. Someone can be shocked, even killed from that condition.

It's not just theory, those shocks have actually happened, even in cases I've seen personally. What you propose is a violation of electrical code and it is unsafe.

On 2017-03-25 by mikerosco2004

I have a picture that i'd like to share but can't cause there isn't an option here.so I will have to explain.any 15 or 20 amp 3 prong receptacle.

i sometimes have to jump an insulated piece of white wire to the ground screw off of the neutral side terminal because since the neutral and ground go to the same ground bus bar in most of if not all boxes I've worked in including my own 2 panel boxes.either there isn't a path through to ground by mc shielding or a ground wire I have no choice but to do this procedure.

i've just stumbled upon this trick on my own in the field to fool the quick receptacle testers and in thinking that this will ground the user from shock.

i wonder if this is a safe work around here in the NE,lol!..codes might frown upon it but like many cancer causing substances can only give you cancer in the state of California and not anywhere else.electric is electric in any part of the world it's just looks different.

On 2017-03-21 by (mod)

Akhila said:
Thank you for the useful information.

On 2017-03-17 by (mod)

Fair question, Tim as the page above is basically an index to articles at InspectApedia.com

Using the little search box just above for "ELECTRICAL OUTLET WIRING" finds two articles you will want to review - then do ask if questions remain

1. ELECTRICAL OUTLET, HOW TO ADD & WIRE - https://inspectapedia.com/electric/Electrical_Outlet_Installation.php
and
2. ELECTRICAL RECEPTACLE CONNECTION DETAILS - https://inspectapedia.com/electric/Electrical_Outlet_Wire_Connections.php

these Q&As are also helpful

3. ELECTRICAL OUTLET WIRING FAQs - https://inspectapedia.com/electric/Electrical_Receptacle_Wiring_FAQs.php

You have to find the wire in the wall, add a junction box (that can't be buried later) to permit getting enough slack to add wires to connect your receptacle, add a box for the receptacle if everything doesn't fit in the first junction box, then do the wiring and secure the box in the wall.

On 2017-03-17 by tim

how do I connect a simple wall outlet to a wire already passing through wall

On 2017-01-23 by (mod) re: how to trace an electrical circuit

There are circuit tracing tools that emit a tone, hooked up in panel. Let's hope nobody buried the junction box.

See ELECTRICAL CIRCUIT ID, MAP & LABEL for details.

On 2017-01-23 by Brett

Anyone have any luck tracing circuits inna mobile home ? Have a service ticket, half the kitchen circuits are out, 12/3 leaving panel and 12/2 feeding kitchen receptacles. Looking for a junction point.

Question: air conditioning system circuit wire sizing

(May 29, 2011) paul macgregor said:

hi , i have a install of a/c its a LG single phase ducted system ,32 amps but the cable run is 55 / 65 meters i think this should be 10mm cable ??? or can 6mm be used

(May 31, 2011) electricaldave said:

Canadian Electrical Code requies that the prober size wire be use for the rated load. By the looks of your unit, I would suggest using a #8 cable. This is rated for 40amps. Wire is rated with 80% load rating and with the lenght of the run, this cable would work best.

Reply:

Thanks Dave.

Recently-posted questions & answers about the building electrical system, originally appearing

at ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR

On 2017-01-23 by (mod) circuit tracing tools

There are circuit tracing tools that emit a tone, hooked up in panel. Let's hope nobody buried the junction box.

On 2017-01-23 by Brett

Anyone have any luck tracing circuits inna mobile home ? Have a service ticket, half the kitchen circuits are out, 12/3 leaving panel and 12/2 feeding kitchen receptacles. Looking for a junction point.

...

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