Ireland/UK Delivery Time


I was just wondering if anyone living in the UK/Ireland has bought an IOTAWatt recently and how long it took to deliver?

Also, where’s the best place to buy a VRT with a 3-pin plug?

Since it’s no longer on I thought shipping might take longer than older posts have mentioned.


I bought one 8 months or so ago.

Great product.

Delivery is a week or so possibly two.

You will need to pay Vat before receipt.

The iotawatt itself arrives in the UK within 4 or 5 days. There is good tracking so you can see progress.

It hits the UK and all goes quiet.

Then the customs agent writes to you. You make the payment and the goods arrive next day or the day after.

In terms of the UK style VT I got mine from openenergymonitor shop with some CTs. I picked up some other CTs from eBay.

1 Like

An alternate source for the Ideal 9V transformer:

1 Like

Thanks Phil, much appreciated.

The CTs from ebay, were they the same brand as what’s on OEM or different entirely?

In theory they are the same brand but they came from China. I don’t know if there is a problem with copying or whether there is one factory and lots of resellers. That said, I can’t tell the difference between the open energy ones and eBay but I didn’t do any calibration tests.

I presume you could fit several to the same cable and see what the variation is.

You can look up the ‘known’ devices in the iotawatt documentation to work out what to order. Sct-013-xxx are the ones I chose where the xxx was the appropriate device for the anticipated current.

If buying lots from abroad/eBay it might be worth splitting your orders to make sure you come in under the personal import vat exemption. The delays are more hassle than the vat (and £8 admin charge from the post office)

1 Like

@philrob, @NiallG,

With IoTaWatt (and OEM stuff as well unmodified) the only model of interest is the SCT013-000 which is a 100A CT. I know there’s a school of thought that a 100A CT is not appropriate for low current circuits, but the SCT013-000 will produce the same results as a 50A CT or a 20A CT when clamped to the same cable with IoTaWatt.

The SCT013-nnn are voltage type CTs with internal burden resistors. They would require modification of the IoTaWatt to use, and moreover, the higher burden causes greater phase shift with no observable increase in accuracy.

1 Like

@overeasy @philrob

Thanks for the info guys, much appreciated.

Do either of you know if there’s 100A CTs with a cable length longer than 1.5m and would still work with the IOTAWatt?

This previous post might be of interest if you need long CT leads.

1 Like

I’m guessing the website in your blog post doesn’t provide CTs with headphone jacks and would require some soldering?

Also in regards to 5v power supply with a 3-pin plug, would a Raspberry Pi power supply work fine?

That unit should work fine.

The 100A SCT013-000 from OEM should work fine with IoTaWatt and are supported in the configuration tables. If they are still selling SCT006 CTs, I can’t recommend them, although they are also listed in the tables and will work. Both have 3.5mm stereo jacks, as do most all SCT013-000 from Ebay or other sources.

1 Like