Single Phase TTR? Which do you like and why?

Looking to purchase a couple of single phase TTRs. I was wondering which Mfg and Model others had used and had good or bad experiences with over the years. Thanks in advanced for any input.


@user200 At one time I would have stated that the AEMC 8510 was a viable option. But the pricing on AEMC equipment has increased quite a bit. AEMC units are great if you aren’t using them daily. They are a box of air compared to more expensive options. They don’t take the vibrations of being in a truck bouncing down the road too well. I own 3 of these units and I get my hands dirty tearing apart the circuit boards and resoldering components on them to keep them ticking. But as I mentioned, I purchased them for around $1800 and now the pricing has surpassed the $3000 mark. You can purchase better branded TTR’s for slightly more and get more durability out of them.

The old Biddle hand cranks are awesome test sets. They are extremely durable and don’t require external power. They are getting harder to find as they are becoming older and been in service for years. Megger makes a newer option that will come with a shocking price tag. I have not used the Megger 550005B yet. It looks like a fancy Biddle unit in a new and clean presentation. I imagine this thing will be a tank for years to come. But with the price tag it holds, it better!

Megger also makes a TTR100-1 which is a handheld unit. This is slightly more expensive than the AEMC 8510. This is a great unit for small transformers. One of the draw backs is that the leads tend to be on the shorter side. Also, larger transformers with higher excitation currents have caused me some problems with using this unit.

Raytech makes another great option. I believe this one costs less than the Megger 550005B, but more than the AEMC 8510 and Megger TTR100-1. Raytech makes some really good equipment. I’ve liked using their stuff. Inventory of these units seems to be a bit on the low side. I don’t know what the lead time looks like. They are imported from Switzerland - I think. Raytech TR-1

Thats about the extent of equipment that I’ve used. Money and Quantity will probably be the biggest factors. But definitely talk to the techs you work with to hear their opinions.


In terms of single phase, I used a classic hand cranked TTR for the good part of my early career. Back then it had Biddle branding but the Megger TTR550005b is essentially an updated design. Never really had a problem with it other than the bulky clamps and keeping the voltage consistent while dialing the ratio in. Never worried about needing power but the self test procedure can be difficult to grasp at first.

Since then I’ve moved to the Hand-held Transformer Turns Ratio Tester (TTR100-1) because of the convienence and digital interface. Much faster and easier to use but the clips are much smaller so you may have trouble using it on larger units. This also comes with an advantage over the old hand cranks because you can test smaller transformers much easier, including PTs and CPTs.

For three phase units, I have personally used the Megger TTRU3 and the TR-MARK III by Raytech. Never had a problem with either.