Help with Equitech 1.5Q power conditioner

@oddiofyl - Please tell me what -60V AC means. :)

I’m familiar with balanced power and even repped one such device (ages ago). Even if that’s how they describe it, it’s not really accurate.

If you doubt me, get a multimeter, and buy an Equitech and measure it yourself.  Send me a picture of the + and - readings. :)

BTW, the output of a balanced power conditioner is not dissimilar from the 220V outlets your big appliances (range, dryer, HVAC, etc.) use.

It’s still not one +120 and one -120 V line. It’s two lines from the same transformer winding that run in opposite polarity. It is impossible to measure +120VAC. You can’t tell one from the other. The only thing you can do is measure the delta between them, which in this case would be 220VAC.

I’ve often wondered, along the same lines if the ideal situation wasn’t actually to run 220VAC to an audio room and use a combined step down and balanced output conditioner. Balanced power to balanced power essentially.

While I don't want to encourage anyone to poke around in a 220V outlet, I really don't!  I can say categorically that if you took the most advanced multimeter on earth to your dryer's 4 prong outlet you can identify 2 hot lines, but cannot identify one as being + and the other - based on the meter's readings.  Impossible.  You could at best identify 2 lines which are either  ground or neutral, and 2 lines which are energized. 

@erik_squires I believe this is what @oddiofyl is referring to. The drawing is showing one cycle in time.

https://www.electronics-tutorials.ws/wp-content/uploads/2018/05/transformer-trans63.gif

The drawing shows a single phase, split phase, power transformer’s primary and split phase secondary winding.

For this discussion use 120V for the primary winding.

Secondary winding:

Center tap of the two windings is the neutral which will be intentionally earth grounded, bonded to the frame/chassis of the transformer enclosure, making it the Grounded Conductor. This Makes the secondary of the isolation transformer a Grounded Power System... (The neutral conductor will not be used for output power. All EGC conductors will connect to the grounded conductor.)

The two outer leads of the secondary are ungrounded, HOT, legs. From one HOT leg to the other HOT leg the voltage is 120Vac nominal. From either HOT leg to ground the voltage is 60Vac.

Neither of the two Hot legs are a neutral. They are both HOT ungrounded legs.

Again, the neutral is the center point of the two 60 volt windings that are connected in series. The neutral is connected to ground which makes the output a grounded power system.

Just because the NEMA 5-15R or 5-20R 120V receptacle has an Identified contact and connection terminal screw does not make the HOT ungrounded 60V to ground conductor a neutral conductor. It is not...

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So, essentially the outlets on the back of the Equitech are wired the same way as old 240V appliances, the kind that had 3-wire cords. Correct? How does it handle floating-ground loads? I’m a bit confused

So, essentially the outlets on the back of the Equitech are wired the same way as old 240V appliances, the kind that had 3-wire cords. Correct?

That seems close, but the house N is not grounded through the Equitech. Or at least should not be. Ye olde (pre 1990s?) dryer DID bond N and ground internally to the dryer. There’s no reason to do that with a balanced conditioner... but I don’t speak for the manufacturers. Who knows what crazy things they do.

The secondary winding on these isolated devices is split. The center of the two coils is bonded to ground, so the outside ends of the 2 coils are each equal and opposite 60VAC.

And herein is a problem which the founder of Jensen transformers wrote about ages ago, that there’s still the possibility for a ground loop. Ooops.

Anyway, what floating ground load?