wire nuts come loose?

[Randyretired]

An open leg on the meter will read as 120 volts on the one side.  The other side will have resistance to the neutral through the remaining circuits still connected to the open side.  That resistance to the neutral could slightly warm the water.

[Kirk W]

9 hours ago, Randyretired said:

The other side will have resistance to the neutral through the remaining circuits still connected to the open side.

The neutral does not connect to the load in a240V connection. The load is between L1 and L2 only. In fact, until recent changes in electrical codes most wiring for 240V appliances had no neutral wire, only L1, L2 and ground.  That is still quite common in older homes for the connections to a dryer outlet, an electric stove, or an electric water heater. If you look at new dryers, they do not come with a power cord but you buy an installation kit with the proper cord as you can use either a 3 prong or a 4 prong plug. My house, built in 2008 has a 3 prong dryer outlet and it has no neutral wire. 

                                                                 

[Lance A Lott]

10 hours ago, Kirk W said:

. The reason that I asked for the explanation is that as a career electrical service technician, I think you missed something. A house has two legs from a 240V transformer that has a center tap tied to neutral and each phase is then 120v to the neutral line. Your water heater element has what amounts to +120V on one end of the element and -120Vtothe other, giving you an effective voltage of 240V. (As AC electricity it is actually two legs that are 180 degrees out of phase but they work in a push/pull effect.) If you remove either of the legs from that element, the result is that no current can flow so no heat. You must have had a bad connection that was dropping about half of the voltage and so lowering the heat capacity. In such case, you would have measured somewhere around half voltage across the element and the other half across the bad connection. Such a poor connection would probably asl show signs of having been very hot. 

I ran a water pump 220 volts by disconnecting one side with a float switch in a tank for years. I had electricians tell me it would not work and other tell me it would.  I was told it would hum and get warm from trying to start. And I was told that was not the case, I thought it would work and it did. No heat no humming.

[oldjohnt]

10 hours ago, Randyretired said:

An open leg on the meter will read as 120 volts on the one side.  The other side will have resistance to the neutral through the remaining circuits still connected to the open side.  That resistance to the neutral could slightly warm the water

 

1 hour ago, Kirk W said:

The neutral does not connect to the load in a240V connection. The load is between L1 and L2 only. In fact

 While the Neutral does not connect directly to a water heater  IE as posted  "The load is between L1 and L2 only" only, to add just a bit to the two comments above, and to offer my opinion as to how Randy could be correct, I suggest this:  NOTE  Anytime I designed a circuit to open a 240 volt L1 to L2 connection I disconnected  BOTH leads similar to how a 240 volt circuit breaker opens BOTH legs WELL DUH LOL.

   Just as a FYI for the non sparkies, of course, in a typical residential 120/240 Volt Single Phase Three Wire service the outer ends of the LV secondary transformer is 240 VAC L1 to L2. However in the center of that transformer winding a wire is connected there which is also connected to mother earth (Neutral) and its then 120 VAC from either L1 or L2 to Neutral. That's two legs or 120 VAC Line to Neutral which are divided up to feed certain household loads (some L1 others L2) and 240 VAC L1 to L2 for say stoves and water heaters and dryers etc. etc.

If there are the two L1 and L2 connections to say a 240 Volt water heater element and if either line is open, there's no 240 VAC sourced direct L1 to L2 current flow through all the element.

NOTE That posted below can obviously depend on a)  If BOTH L1 and L2 are open/disconnected to an element ORRRRRRRR   b) Only one leg is disconnected.

 However (A) Its still 120 VAC from L1 or L2 to Neutral and either L1 or L2 (unless both open) could be connected to a heating element.

                         Again I always opened BOTH.   

                  (B) Back at the main panel N is bonded to the Green/Bare Equipment GroundING Conductor

                  (C) And the Equipment GroundING Conductor  is bonded to the outer steel case/frame of the water heater.      IE      THERE CAN INDEED REMAIN  (be it indirect and even if a short or interconnection is required)  A  COPPER WIRE CONNECTED CURRENT PATH TO NEUTRAL (via Neutral and Ground bond in the main panel) IN A 240 L1 TO L2  VOLT WATER HEATER even if no Neutral wire is ran to it !!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

                  (D) Those heating elements are connected to L1 on one end, and L2 on the other, are immersed in water, and there are other inter connections such as thermostats etc.  IE BOTH L1 and L2 are ran throughout the water heater and its 120 VAC from

                         L1 or L2 to the Equipment Grounding Conductor which is bonded to the water heaters conductive metal case/frame 

  

THEREFORE if there were to remain a live hot L1 or L2 connected to only one end of a 240 volt heating element and IFFFFFFFFFFF there was a circuit path (shorts/faults/interconnections) it could still be possible for current flow and the resultant I Squared R heat produced to heat some water.

 

 That's my story n Ima stickin to it lol

 

 John T Longggggggggg retired n rusty power distribution engineer and the memory fades and things change SO NO WARRANTY ANY OF THIS IS CORRECT   I just understand where Randy is coming from and how there can still be 120 volt sourced current flow which can heat water (given a L1 or L2 to Ground current path)  to some degree even though the water heater is only a 240 volt L1 to L2 appliance BECAUSE REMEMBER THE HEATERS CASE/FRAME IS STILL ELECTRICALLY CONNECTED TO NEUTRAL VIA THE MAIN PANELS NEUTRAL/GROUND BOND  

[beemergary]

12 hours ago, Kirk W said:

. The reason that I asked for the explanation is that as a career electrical service technician, I think you missed something. A house has two legs from a 240V transformer that has a center tap tied to neutral and each phase is then 120v to the neutral line. Your water heater element has what amounts to +120V on one end of the element and -120Vtothe other, giving you an effective voltage of 240V. (As AC electricity it is actually two legs that are 180 degrees out of phase but they work in a push/pull effect.) If you remove either of the legs from that element, the result is that no current can flow so no heat. You must have had a bad connection that was dropping about half of the voltage and so lowering the heat capacity. In such case, you would have measured somewhere around half voltage across the element and the other half across the bad connection. Such a poor connection would probably asl show signs of having been very hot. 

I didn't miss something. The moral of the story was by just using a light meter I didn't know I wasn't getting 110 volts down each leg and only one. The wire nut in the meter box had come off and wires had separated loosing all connections. I built this house and did the wiring. The day the power co. set the transformer the guys that ran the power had beer with their lunch. The wire nut was have melted probably fron arching from not being tight.

[oldjohnt]

1 minute ago, beemergary said:

The wire nut was have melted probably fron arching from not being tight.

 SOOOOOOOOO POSSIBLE  Again "Improper Installation" anytime a loose/resistive  connection starts arcing n burning and producing heat and carbon and current flows through that resistance its I Squared R heat being developed which can melt wires etc and even totally open the circuit.

John T

[Kirk W]

1 hour ago, beemergary said:

The wire nut in the meter box had come off and wires had separated loosing all connections.

Leaving only the 1 wire connected?

[Randyretired]

3 hours ago, Kirk W said:

The neutral does not connect to the load in a240V connection. The load is between L1 and L2 only. In fact, until recent changes in electrical codes most wiring for 240V appliances had no neutral wire, only L1, L2 and ground.  That is still quite common in older homes for the connections to a dryer outlet, an electric stove, or an electric water heater. If you look at new dryers, they do not come with a power cord but you buy an installation kit with the proper cord as you can use either a 3 prong or a 4 prong plug. My house, built in 2008 has a 3 prong dryer outlet and it has no neutral wire. 

                                                                 

If the water heater was the ONLY thing connected to L1 and L2 in the entire house your analysis would be correct.  However,  that is not the case in most houses.  Which ever side is open is still connected to other circuits and many are 120 volt circuits that are connected to the neutral. Current will flow back through these circuits to the neutral.   The open is at the meter so all of the open side is still bonded together in the house.  I know this because I have seen it.

[Sehc]

Seems this thread moved to different subject. Oh well, I'm going back a few. I don't want wire nuts in my RV. I also don't want solid wire in my RV. There are too many things that can go wrong. 

[Lance A Lott]

1 hour ago, Sehc said:

Seems this thread moved to different subject. Oh well, I'm going back a few. I don't want wire nuts in my RV. I also don't want solid wire in my RV. There are too many things that can go wrong. 

Every camper, RV I ever worked on had both.

[Kirk W]

10 hours ago, Lance A Lott said:

Every camper, RV I ever worked on had both.

I don't remember for sure how things were done back when I first looked inside an RV electrical system that had 120V so they may have used stranded wire back then but all that I have seen in recent years used stranded wire and crimp connectors for 12V and standard Romex type wire & wire nuts for the 120V side of things. There are several reasons for their use of solid wire for the 120V but cost and availability are probably the main ones. 

[oldjohnt]

11 hours ago, Lance A Lott said:

Every camper, RV I ever worked on had both.

Lance, I've owned campers 48 years, was a used dealer and best I recall an RV used BOTH solid (often 120 VAC) and stranded wire (often 12 VDC). I prefer stranded for better vibration tolerance, flexibility and ease of installation but it may cost more. I doubt the RV industry will go to all stranded but??? Of course a person can rewire using all stranded if he prefers and there are splice methods OTHER THAN wire nuts.  The more typical wire nut failures I saw were solid to stranded. If not installed correct the stranded gets pushed down is loose versus solid to solid. If stranded leads are tinned and/or splices are soldered that improves the connection integrity.  

Back to water heaters: When I was an EE at a huge Naval Industrial facility with 3000 employees and hundreds of buildings and water heaters an often heard complaint was the water wasn't very hot. I saw a lot of open elements,,,,,,,,,,,shorted elements,,,,,,,,,,,,shorts to case/frame (bonded to Ground which is bonded to Neutral in the panel) other shorting current paths and/or back feeds from other circuits,,,,,,,,,,other faults causing 120 instead of 240 on a 240 element  NOW THAT DONT HEAT WELL LOL. Sure wire nut failures happen mostly due to improper installation.

NOTE I see many more problem with those RV/Mobile home 120 volt push on (no screws) receptacles then wire nuts

Best wishes yall keep safe. Fun thread for us sparkies at least

John T  Live from McKinney Falls in Austin Texas

[Randyretired]

The wiring in a typical RV certainly could be better but it usually will outlast the RV.  Our current 5er is 20 years old and I have spent a lot of time remodeling it.  The wiring has not been much of a problem.  The worst wiring problem on any of the RV's we have owned was with stranded 12 volt wiring to the running lights.  A number of years ago we purchased a one year old 5er that was like new.  We were excited to get such a nice almost new 5er but on the way home suddenly the running lights failed.  The fuse had blown so I replaced it.  A few more miles down the road it happened again. At home I began to look for the problem but sitting in the driveway all tested good.  To make a really long story short, the problem was a stranded 12v wire had fallen down behind the fiberglass siding and when the frame would flex just right it squeezed the wire against the frame.  It took me weeks to find it.

[ALLOY]

On 12/16/2018 at 7:11 AM, oldjohnt said:

Lance, I've owned campers 48 years, was a used dealer and best I recall an RV used BOTH solid (often 120 VAC) and stranded wire (often 12 VDC). I prefer stranded for better vibration tolerance, flexibility and ease of installation but it may cost more. I doubt the RV industry will go to all stranded but??? Of course a person can rewire using all stranded if he prefers and there are splice methods OTHER THAN wire nuts.  The more typical wire nut failures I saw were solid to stranded. If not installed correct the stranded gets pushed down is loose versus solid to solid. If stranded leads are tinned and/or splices are soldered that improves the connection integrity.  

Back to water heaters: When I was an EE at a huge Naval Industrial facility with 3000 employees and hundreds of buildings and water heaters an often heard complaint was the water wasn't very hot. I saw a lot of open elements,,,,,,,,,,,shorted elements,,,,,,,,,,,,shorts to case/frame (bonded to Ground which is bonded to Neutral in the panel) other shorting current paths and/or back feeds from other circuits,,,,,,,,,,other faults causing 120 instead of 240 on a 240 element  NOW THAT DONT HEAT WELL LOL. Sure wire nut failures happen mostly due to improper installation.

NOTE I see many more problem with those RV/Mobile home 120 volt push on (no screws) receptacles then wire nuts

Best wishes yall keep safe. Fun thread for us sparkies at least

John T  Live from McKinney Falls in Austin Texas

AC and DC marine wire has to be stranded and crimped and using electrical tape is a no no.  Differences in the standards  must that there are fewer deaths given that it is easier to escape a RV fire.

 

 

[oldjohnt]

8 hours ago, ALLOY said:

AC and DC marine wire has to be stranded and crimped and using electrical tape is a no no.

While I've seen and repaired more RV's then the typical Joe, I "usually" saw wire nut or crimp connections and they "usually" did NOT have tape over them.....Ive seen more tape used in residential 120 VAC wiring then in RV's, but again I've pretty well seen about anything and everything out there lol some proper some not...……...

John T

[Carlos]

10 hours ago, ALLOY said:

AC and DC marine wire has to be stranded and crimped and using electrical tape is a no no.  Differences in the standards  must that there are fewer deaths given that it is easier to escape a RV fire.

 

 

 

I wish there were an RV version of ABYC to set standards like that.  I've owned and worked on a lot of boats, and carefully studied the ABYC requirements; so logical.  And each one was written in blood and fire.

I've never worked on an RV that didn't have wire nuts and some amount of solid wire.  My brand new one has real Romex Simpul, which I believe is always solid, but not absolutely sure.  I haven't taken any connections apart.  There are wire nuts, and they are very thoroughly taped over.  There's also one stupid move...  Someone got lazy and used a black wire to extend a white neutral wire from the converter to the neutral bus.  Sigh.

 

[Sehc]

In Home Depot I saw wire nuts with sealant inside. They were recommended for solid as well as stranded wire.

[oldjohnt]

58 minutes ago, Sehc said:

In Home Depot I saw wire nuts with sealant inside.

Similar experience,  in Home Depot or Menards I saw wire nuts for sale that had a breakable light plastic seal with dielectric grease inside them listed for use in damp locations as I recall ?? sure they also were suitable for solid   OR   stranded wire.

  John T

 

[Carlos]

I have a bag of those for use with irrigation controllers and landscape lighting.  Are they allowed for high voltage use?