Testing power to pump with a multimeter

[mikeyw]

Hi,

I've got a sewage pump that is broken. Before i start the expensive job of replacing i just want to check their is power to it using a multimeter. I've checked the fused spur and trips and all appear well but wanted to make sure there is a current passing through the cable into the pump itself.

I'm a complete novice but have a basic multimeter from screwfix.

Please could you advise what settings i need to use on the meter to test the cable ?

Cheers,
Mike.

 

[stem]

It depends upon the meter and the voltage you are reading. If the pump is mains operated, and you want to check there is power to the pump across the Live and Neutral, then usually you need to set the multimeter to measure AC Voltage, and then select the highest value above 230v (UK mains) Some meters have dials or buttons to select this, others have different sockets to plug the test leads in. Some have an autorange facility and will select the right voltage for you automatically.

If you want to test the continuity of the cable, it should be disconnected from the mains and then the end of each wire connected to the multimeter which would be set on ohms, and tested individually. The multimeter will provide its own power internally for this function

If you post details of your multimeter, or a link to the item on the Screwfix website, someone will be able to provide a more definitive answer.

Edit: There is a video here that may help.

 

[ericmark]

I would look for some where to safely clamp the meter on, I use some thing like this

the other option if on a plug is something like this

using the amp range with a hard wired meter is not that easy, you have to wire it in series, it depends on access, some times you can lift one end of a fuse and put meter between fuse and fuse clip, but normally this is only good for extra low voltage as with low voltage (230 Vac) normally there is no access to the fuse.

Even with a meter like this

you need to still get access to the cables, and you can either measure the line or neutral but not both, so I had to make a short extension lead to get access to just the line, so if plugged in one of these

is easy safe way.

 

[mikeyw]

Guys - thanks for the advice. Would a volt pen be a sufficient test as the cable is hardwired from the fused spur.

 

[bernardgreen]

I've got a sewage pump that is broken.

What make and type ?
Does it have a macerator driven by the same motor ?

It is not un-common for a motor driving a macerator to appear to have failed when in fact the macerator has been jammed by rags or other material flushed down a toilet and the notor is stalled.

There should be a slow acting over current trip that operates if the motor has been stalled for more than a few seconds. This will cut the power to prevent the stalled motor over heating. This is NOT the MCB which provides a different safety cut off for an electrical fault in cabling and / or motor.

Photos would help.

 

[stem]

Guys - thanks for the advice. Would a volt pen be a sufficient test as the cable is hardwired from the fused spur.

Volt pens have some uses, but are limited and unreliable. They will detect there is a voltage of some value present (e.g. between 24 and 1000V), but not tell you what it actually is.

Normally a neutral won't cause them to light, but can do under some circumstances.

 

[endecotp]

make sure there is a current passing through the cable into the pump itself.

Do you understand the difference between voltage and current?

Some of the answers above are taking literally your mention of current. Others are telling you how to measure voltage, which might be a better thing to do first.

Volt pens are useless. Someone recently claimed that his lights up when he touches his head.

 

[ban-all-sheds]

Someone recently claimed that his lights up when he touches his head.

 

[just pumps]

Most likely either the thermal cut outs or the micro switch has failed, what make and model pump is it? And how old?