plumber dug through electrical cable

[notenoughtoys]

a plumber doing some work recently, dug up the power to an external pump and did the usual wrap it up in gaffer tape and say nothing. It appears moisture finally found it's way into the line and tripped the circuit breaker. I've dug it out and the conduit is smashed/missing for around 400mm. Is there some kind of sleeve I can get to join the conduit again and seal the line?? I obviously don't want to have to pull the whole line up to repair it.

This is just an example of the quality of the work this guy did overall, I've already given up getting him back to rectify poor workmanship so I'll be doing it myself and of course because i have a trench open, it is about to rain for the first time in ages

Cheers

bob k

[silentC]

Electrical conduits aren't necessarily water tight. If it tripped the breaker, then the wire must be damaged too? Sounds like you need a sparky to me.

[Ashore]

A sparkey would proberly isolate the cable cut out the damaged area of cable and conduit , put in some new conduit with the cable inside , crimp and tape the cable each end and then join and glue the new section of conduit to the old at both ends , course I couldn't suggest you do this you would need a sparky

[Notsquare]

I work with electrical engineers and we build underwater cameras. In your case, either you or the spark, should buy a metre of heat shrink made by cabac available at electrical wholesalers. This is the stuff with the glue inside. You will need to bare enough conduit so that you can run the heat shrink after you have cut the cable up the loose end whilst you work on the join. Either use terminals or solder the wire, making sure you cover them with a smaller diameter version of the same shrink stuff. Stagger the join so that there is no chance of contact between each join. Then slide back the the larger diameter heat shrink and use a hot blow gun or similar. You will know that you have a positive seal, because the air inflates the centre when you shrink each end in turn. You could then wrap this with some heavy duty mesh similar to what is used to protect the base of galvanished power poles. Or more conduit, split in half and then cover with tape. The heat shrink is the best stuff.

[notenoughtoys]

Electrical conduits aren't necessarily water tight. If it tripped the breaker, then the wire must be damaged too? Sounds like you need a sparky to me.

Thanks guys, I should have mentioned that I intend to replace the damaged cable, that isn't too hard just more $$$ (anyone recommend a good place to buy electrical cable in western sydney at the right price). I just wasn't sure how to get conduit into the middle of the line once I did this, the heat shrink sounds a good solution, I shall try and source some of that.
It's beginning to sprinkle outside now. The power was to a submersible pump I have in one of two underground stormwater tanks, it's role is to pump the water into the second tank which has the pressure pump hooked up to it. They are set up like this because it is part of a bio septic system made redundant when the sewer came through. Now, because the first tank is full and I can't get at it, any rain water will be diverted to the overflow and run to waste while the other tank is empty ,
it jus goes on, and on and on and on and on....
(I'd say b#@%y plumber here but don't want to upset any forum members

[elkangorito]

There are many methods used to join cables, depending upon the installation.

In your case, moisture/water is involved. The only proven & reliable method I have used is a resin kit. These kits are readily available at electrical wholesalers & will provide waterproofing if applied correctly. The kits are made by 3M (Scotchcast). Heatshrink & glue will not provide the required waterproofing & "fault current withstand" properties. The cables waterproof, insulation, temperature rise & fault current integrity MUST be maintained.

The PVC conduit is only there to provide mechanical protection & as such, can be replaced with anything that will provide the same minimum mechanical protection.

Needless to say that an electrician should do ALL of the cable reparation work.

Here is a link to the products that I have used in similar situations to yours;

http://solutions.3m.com/wps/portal/3...beDP16W8FB2Ngl

EDIT: Soldered cable joins must not be used unless they are also crimped properly.

[malb]

If you are going to get a sparky to replace the cable, they should be able to splice the conduit first.

Needs a metre or so of open trench length (more as conduit diameter increases), trim both ends of damaged section, cut replacement section to length with expanded coupling on one end, expand the other end to form a second coupling, lift both sections of original conduit and insert into into the expanded coupling and return to ground.

The pull replacement cable through and connect.

Conduit is normally supplied in 4m lengths so often has a number of joins over a run.

[elkangorito]

Below is what MUST be done with regard to joining cables (current regs).


3.7 ELECTRICAL CONNECTIONS.
3.7.1 General.
Connections between conductors and between conductors and other electrical equipment shall provide electrical continuity and adequate mechanical strength.

3.7.2 Connection methods.
3.7.2.1 General.
The selection of the method of connection shall take account, as appropriate, of the following:
(a) Material of the conductor and its insulation.
(b) Number and shape of the wires forming the conductor.
(c) Cross-sectional area of the conductor.
(d) Number of conductors to be connected together.
(e) Temperature attained by terminals in normal service such that the effectiveness of the insulation of the conductors is not impaired.
(f) Prevention of entry of moisture and the siphoning of water through any cable or wiring enclosure.

3.7.2.2 Preparation for connection.
The insulation on a conductor shall not be removed any further than is necessary to make the connection. For connections between insulated conductors the connection shall be insulated to provide a degree of insulation not inferior to that of the conductors. Any damaged insulation shall be reinstated.

3.7.2.3 Loosening of connections.
Connections shall be made so that no loosening is likely due to vibration, alteration of materials or temperature variations to which the connections are likely to be subjected in normal service.

3.7.2.4 Retention of stranded conductors.
The ends of stranded conductors shall be secured by suitable means so as to prevent spreading or escape of individual strands. They shall not be soft soldered before clamping under a screw or between metal surfaces.

3.7.2.5 Mechanical stress.
All cables and conductors shall be installed so that there is no undue mechanical stress on any connection.

3.7.2.6 Soldered connections.
Where a soldered connection is used the design shall take account of creep, mechanical stress and temperature rise under fault conditions.

3.7.2.9 Underground cables.
Connections in underground wiring shall be sealed to prevent the entry of moisture.

3.7.2.10 Earthing conductors.
In general for tunnel type connections, at least two screws shall be provided to maintain effective clamping of the conductors.
This requirement need not apply where —
(a) one clamping screw, in direct contact with the conductor, is provided at the fixed terminals of electrical equipment such as junction boxes, socket-outlets, and lampholders; or
(b) one screw is provided in bars or links and the outside diameter of the screw is not less than 80% of the tunnel diameter; or
(c) one screw is provided in connections arranged so that the conductor is clamped by suitable ferrules or plates in direct contact with the conductor. Where soldering is used for the jointing or connection of earthing conductors, the earthing conductors shall be retained in position by acceptable means independently of the solder.

3.7.3 Enclosures.
An enclosure may be required to provide adequate mechanical protection and protection against relevant external influences.

5.5.4.3 Protection against corrosion.
Earthing conductors, and any associated fixing devices, shall be protected from corrosion, including the effects of moisture or contact with dissimilar metals. Earthing conductors and associated fittings and fixing devices shall comply with the following requirements:
(a) Underground and damp situations All joints and terminations installed in an underground location or other damp situation shall be sealed to prevent the entry of moisture. All associated fittings and fixing devices in such locations shall be constructed of, or protected by, corrosion resistant material.

[NCArcher]

Below is what MUST be done with regard to joining cables (current regs).


3.7 ELECTRICAL CONNECTIONS.
3.7.1 General.
Connections ............
.......of, or protected by, corrosion resistant material.

It really is not necessary to post wiring regulations verbatim.
The job must be done by a qualified electrician and he already knows the regs.