Discouraged!

The Junk Drawer is for those Off Topical discussions where we can ask questions of the community that we feel might have the ability to help out.

Moderator: Harold_V

User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Discouraged!

Post by Harold_V »

Hey, guys!
Some of you may be aware that I've spent a great deal of my time on getting an old motor/generator induction furnace operational. Fact is, I've been successful and have operated it a few times, but not without issues.

One of the problems I'm having is with the kilovar meter. It was fully rebuilt by Hickok many years ago but was put in storage when it was received because I was nowhere near having need. That was years in the future, although I had no idea how many it would become. In the meantime, Hickok has abandoned all support on analog meters. I am now stuck with a meter that appears to be non-functional, and operating the motor/generator without its use is asking for more problems than I care to discuss. I live in fear of destroying the generator, which would spell the end of this venture.

When I first installed the kilovar meter I discovered that it wouldn't function. After ascertaining that I was on my own, I opened it up to discover that the pivot was out of the bushing on the hairspring end. I carefully reinstalled it and reinstalled the meter. Since then it has dislocated a couple more times, and with almost no effort, but the meter appeared to function after the pivot was relocated, as it displayed lead and lag as it's supposed to do.

I've tried to diagnose the problem and It appears that the pivot, a steel point, isn't running in a ruby bushing, but ON a ruby bushing, as if it was improperly made and has no hole. Mind you, I don't know that to be the case---but it makes sense as the point appears to wander about when it should be held in a common location. The pointer is also irregular, which lends support to the idea that the pivot isn't staying where it belongs.

Today I fired up the induction furnace. It ran properly the last time I did so, but, today, the kilovar meter didn't function at all. It was removed and proven to be free, then re-installled. Nothing. I did a voltage check across the terminals and got a reading indicating that the meter was receiving a signal. Unfortunately, I didn't have the presence of mind to do a continuity test on the meter while it was removed. This thing is housed in a heated shop and is never abused or handled by anyone but me. I can't imagine why the meter has stopped working, as there's no apparent reason.

What I'd like to do is replace the analog meter with a solid-state meter, but I don't have a clue if that's possible. That way I wouldn't be stuck with a meter that can't be repaired. Is anyone here versed well enough on metering that they might be able to guide me? If so, the Hickok meter has the following information printed on the face:

Hickok Model 69
E.S.=250 VARS
Volt limit 150
Amp limit 7.5
P.T.R. 400/100
C.T.R. 200/5
For 3KHz use

Thoughts?

Thanks!

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Bill Shields
Posts: 10460
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Discouraged!

Post by Bill Shields »

I Know yokogawa still makes them.

Do not get discouraged...you start to sound like be

Google VAR meter and you will see many offerings.

Hang onto wallet.

You Might try hickkckmeters com

I know that are tube tester repairs....but they might know someone

Or call pc-s.com and see what they have as a replacement.

Is someone made an analog, there is a digital replacement
Too many things going on to bother listing them.
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Discouraged!

Post by tornitore45 »

Why one need a KWAR meter to safely run a rotating generator?
I assume KVAR means Kilo Volt Amper Reactive
A generator is limited by VoltxAmpere which is called Apparent power.
Mauro Gaetano
in Austin TX
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Discouraged!

Post by Harold_V »

Because there's an ever changing capacitance, capacitors are shifted in or out of the circuit to control power factor. Allowing it to lag is damaging to the generator (creates excessive heat and is inefficient, apparently). For that reason one must have a method of determining power factor. The kilovar meter is that method. Take note that the meter is redlined on the lag side.

My explanation is likely somewhat weird---I am not an electrical person. I may not have a firm understanding and may be using improper terminology. That's why I turn to you folks--the ones who know this stuff. Please feel free to correct me.

H
Attachments
DSC00051.JPG
DSC00051.JPG (190.28 KiB) Viewed 2720 times
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Bill Shields
Posts: 10460
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Discouraged!

Post by Bill Shields »

So it is a phase angle meter?
Too many things going on to bother listing them.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Discouraged!

Post by Harold_V »

In a sense, yeah! The meter measures the phase angle between the voltage and amperage, which is not in lockstep. When not in unison, power generated is lost to the purpose of melting. It is in constant change until the charge is fully melted. Even then, the slightest change, either by adding more metal or pouring off some of the molten metal, it changes. Without a meter, you have no clue if the unit is in balance, or not.

Solid state units do all of this without the operator intervening. This isn't one of them. Frankly, it's very primitive when compared to them, but I don't happen to have a hundred thou to dedicate to this project! :wink:

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Discouraged!

Post by Harold_V »

I went out on a limb and called the maker of these meters. They were somewhat encouraging, although I suspect it won't bear fruit. The gal I spoke to suggested I send them a picture of the meter along with its original part number. They'll do some research to see if they can provide a replacement. She also suggested that the plant where they were made is still in operation, but they made clear to me a few years ago that they no longer support the analog meters. Still, who knows? My sob story may be encouragement for them to take a look. We shall see!

Bill, thanks for your comments. I'm now going to follow up on what you provided to see if I can learn something. I hope so, as I don't feel good about abandoning this project after dedicating so much of my life to it, to say nothing of the thousands of dollars I have spent.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Bill Shields
Posts: 10460
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Discouraged!

Post by Bill Shields »

Picture of the wiring connections would help.

Is the motor/ generator 3 phase output?
Too many things going on to bother listing them.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Discouraged!

Post by Harold_V »

Bill Shields wrote: Tue Feb 07, 2023 6:49 pm Picture of the wiring connections would help.
Pretty simple, Bill. A set of connectors for the voltage, and a set for the amperage. Sorry for the blurry picture. These old hands aren't very steady anymore.
DSC00052.JPG
DSC00052.JPG (189.95 KiB) Viewed 2697 times
Is the motor/ generator 3 phase output?
Single phase, 3,000 Hz, 400 volts. There's a high frequency transformer that allows stepping up the voltage in 50 volt increments up to 800 volts. The meter sees samples of voltage and amperage, not the actual output.
Face of the meter shows this:
E.S.= 250 VARS
VOLT LIMIT 150 AMP LIMIT 7.5
P.T.R. 400/100
C.T.R. 200/5
FOR 3KHZ USE

The original part number is Hickok 690-068

I've inquired of pc-s.com (by email). We'll see what they have to offer. They do show analog KVAR meters on their site, although just two wire. Don't know what to make of that.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Bill Shields
Posts: 10460
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Discouraged!

Post by Bill Shields »

How do these connect to their source at the other end? Interested in how it samples current and voltage

Admit I am fishing .. just trying to understand.

I am a mech engr by training.....but that was 50 years ago...
Too many things going on to bother listing them.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Discouraged!

Post by Harold_V »

Bill Shields wrote: Tue Feb 07, 2023 7:47 pm How do these connect to their source at the other end? Interested in how it samples current and voltage

Admit I am fishing .. just trying to understand.
I'll have to take a look at the schematic before I an answer that, although I do know that there's a current transformer somewhere. Fact is, it was a part of one of the other meter assemblies, which was replaced when I had meters rebuilt back in the mid 90's. My memory of how this thing is wired isn't reliable and there's way too much to try to remember. I was fortunate that when I first inquired of Ajax they bent over backwards and provided me with endless information, including two sets of prints. They no longer cooperate with me, most likely because of some perceived liability issue. They cautioned me that it could kill me. I know that. So can my truck. So can my neighbor. I just hope that doesn't happen.
I am a mech engr by training.....but that was 50 years ago...
Doesn't matter when it was, Bill. What matters is your mind. If you are open to learning and open to the idea that others may know things you may not, you're good to go. I try to do that and I can't lay claim to any education. I was fortunate to graduate high school, and don't really know how I did. I put forth no effort, never took books home, never did homework. I was a lousy student. The only thing I had going for me was my insatiable curiosity. That's what drives me today, even without any formal education. I'm not educated, but I'm not a fool, either. There's a huge difference between being educated and being smart. The world is filled with educated fools. Events of recent years are pretty much proving that, but we can't really go there (against board policy).

You've been a lot of help, Bill. I read all of your posts. We don't always agree, but I feel we both learn something.

I'll try to take a look at the schematic tonight. I'll report what learn, if anything.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
Bill Shields
Posts: 10460
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Discouraged!

Post by Bill Shields »

do the wires on the meter connect DIRECTLY to something in the system?

Or maybe to a 'donut' transformer that is 'wrapped around' another wire - called an induction pickup.

it would make sense to me that both are on donut transformers around other wires...

if that is the case, I think that there is probably a straightforward solution to your need.

ever seen an AMP METER for A/C?

it does not connect directly to the wire on which you are measuring - it has a 'clamp on' that goes around the main wire in which it is measuring the current.

if this is what I think it is - where you have two 'clamp on' (called induction) connections to what it is measuring -> this may be more straightforward than you feared.
Too many things going on to bother listing them.
Post Reply