Can anybody tell me how to use a growler?
It can get a little wordy so here's a copy I made a while back. It's a Word document. If it loads.
ARMATURE TEST.doc (78.3 k)
The very basic growler is pretty easy. Place the armature on it and apply power. Now, use a hack saw blade or other piece of flat metal and run across the winding segments. If the blade is magnetically attracted to the armature it is no good. You will have to rotate the armature to test the other side.
I was typing as Ken posted. I'm sure his document provides details for a growler with the leads.
Disregard Fig. 2-20. You can't use that test on the Model T armature.
Ken, can not open that. Do you have a different link?
It's a MS Word document uploaded to the forum. I just tried it and it worked. You need Microsoft Word or a compatible reader. I could email it to you but you would still need MS Word.
Thanks guys...this will keep me busy this afternoon.
From the Word Doc -
ARMATURE TEST.—There are two practical tests for locating shorts, opens, and grounds in armatures—the growler test and the bar-to-bar test. To test for short circuits, place the armature on the V-block of the growler and turn on the current. With a thin metal strip (hacksaw blade is good) held over the core, as shown in figure 2-17, rotate the armature slowly through a complete revolution. If a short is present, the steel strip will become magnetized and vibrate. To find out whether the armature coils of the commutator are short-circuited, clean between the commutator segments and repeat the test. Should the thin metal strip still vibrate, the armature is short- circuited internally and must be replaced. Not all armatures can be tested for short circuits by the method just described. These armatures can be identified by excessive vibration of the saw blade all around the armature during the test. With these armatures, test for short circuits by using the milliampere contacts on an ac millimeter, as shown in figure 2-18. In doing so, keep the armature stationary in the V-block and move the contacts around the commutator until the highest reading is obtained. Then turn the armature to bring each pair of segments under the contacts and read the milliammeter at the same time. The readings should be nearly the same for each pair of adjacent bars. If a coil is short-circuited, the milliammeter reading will drop to almost zero. Test the armature for grounds by using the test light circuit, which is a part of most modern factory- built growlers (fig. 2-19). Place the armature on the V-block and touch one of the test probes to the armature core iron. Touch the other probe to each commutator segment in turn. If the armature is grounded, the bulb in the base of the growler will light. In contacting armature surfaces with the test probes, do not touch the bearing or the brush surfaces of the commutator. The arc would burn or pit the smooth finish. Replace the armature if it is grounded. In testing individual armature coils for open circuits, use the test probes, as shown in figure 2-20. Place them on the riser part of adjacent commutator bars, not on the brush surfaces. If the test lamp does not light, there is a break some where in the coil. Repeat this test on every pair of adjacent bars. Do this by walking the probes from bar to bar. Should you find an open coil, the fault may be at the commutator connectors where it is possible to make repairs with a little solder. If a coil is open-circuited internally, the armature should be discarded or rewound.
Figure 2-17.—Using growler.
Figure 2-18.—Testing for a short circuit.
Figure 2-19.—Testing armature for grounds.
Thanks Walt! As you can tell, I didn't spend a lot of time on paragraph formatting. I made it for myself and wasn't planning on publishing it since it came from another source. Those that need it can format it into a more readable format. Sorry.
Here is a PDF of Ken's file.
ARMATURE_TEST-380582.pdf (175.7 k)
Thanks Walt, Ken & Bob.
Don't be sorry Ken...you've been a big help.
Is Acrobat Reader format (PDF) better:
ARMATURE_TEST.pdf (126.1 k)
Bob and Michael thanks both links worked. I have a non Microsoft word program and couldn't get it to open in it.
While you are on growlers, I've never used one but think I have one. It has a light bulb, not a meter. It looks similar to the one posted. Anyone know it it might be a growler? Thanks PK
If it has a heavy looking vee on top it probably is.
If you could post a pic it would help.
There's probably hundreds of manufactures of growlers over the years but they all have a common design. They will have an AC transformer with extended core laminations in the shape of a V or U. If you can post a picture it would be easier to confirm.
After looking at the manual posted here, It looks like the meter was replaced with the light bulb set up. How would this work? What type of meter should I look for? PK
It looks shop made. It also looks like the wiring has seen better days. The bulb is line voltage so it can't be simply replaced with a gauge. The gauge and the bulb are two different tests. And that continuity test (bulb) using line voltage is dangerous. Better to park that one on a shelf next to the water pump.