How to use a growler?

[DanM]

I picked up a used growler at a swap meet, without any paperwork. Can any one provide basic operating guidelines?

THX!!

[Glenn]

have not used one in 30 or so years but try this site I think it will help you

http://www.tpub.com/basae/28.htm

moose

[T. Cotten]

The Service Manual gives instructions.
One important note that is not stressed in the Service Manual, however, is:

Do not grab the commutator while the armature is excited!

....Cotten

[andy at wash]

growler

install armature in v turn on machine pass a screwdriver over the steel bars holding the handle of course if the screwdriver is drawn to any bar thst one is shorted or is it the other way around you can turn the armature with power on

[George Greer]

How can someone test a armature, without having a Growler.??

I have a Digital Fluke 87II at work.......no growler, so what to do now??

Thanks.

George

[T. Cotten]

George!

Electricity mystifies me, but,
I believe the growler is required to apply enough power ("potential"?) to display a short that a very small current, such as a test meter provides, cannot.

My growler has 110v test leads (along with it's electromagnet "V"), limited only by the size of the bulb in the circuit.

The electromagnet will also display a short by magnetizing the core, making a sawblade held lengthwise over the faulty core segment to vibrate wildly.

The third part of the test is to rotate the armature upon the magnet (That's when you must not grab the commmutator!) incrementally to then bridge across commutator segments in order to produce a spark, usually at about "two o'clock" from the vertical axis.
I think a lack of a spark can be either an "open" link between loop-connected commutator segments (such as when the solder has spit out from over-heating), or a short between segments of loops that are supposed to be separate (such as when there is dirt or carbon in the undercut mica separations).

As I noted earlier, the Service Manuals give excellent instructions.

....Cotten

[jmanjeff]

look on ebay for growlers i got one for 35 bucks

[George Greer]

So I gather, that without haveing a Growler to test an armature, many generators may be laying around that are actually good.

I am still curious.......why there's not an alternate method to test armature's..

George

[bmh]

Probably because an armature or a whole generator (actually a dynamo) is more than just wiring and electricity. The whole process depends on the the creation and manipulation of magnetic fields. I believe a growler lets you test those magnetic fields, that simply can't be done with a multi-meter.

[DanM]

armature testing

I used the growler per the guidelines all posted, plus found plenty of literature on the web.

I was in the servo motor manufacturing business for a while, and do know that some type of problems simply don't show up with a multimeter because there is a lack of energy required to identify what is a short when the motor is powered and under load. Like a spark jumping a gap, the windings can look open to the laminations with a multimeter, but when a HiPot tester is used, and 250 v is applied the shorts show up readily.

When you use the growlers 2 leads to check between bars and between the comm and the laminations, you have 120 volts of pressure, compared to a 9v battery in the meter.

I'm not yet sure how to describe the effects of the electromagnet, except that it creates the field in the laminations. A motor wouldn't work well if the armature core was a solid chunck of steel, the thin laminations are part of developing the lines of magentic force. Sorry I cannot describe this fully. I'll try to follow up more intelligently.

[23JDCA 808]

Dan. I think you, and others, have done a good job of explaining this. I got a BS in th 1960's in Physics and some very basic things still appear to be magic. I'm just glad that most of it still works. ...bill in oregon