Q: How to use an inductive probe?

Jan 12, 2006 7 Replies

Our door bell stopped working a few months back and I've been trying to figure out what might be wrong. The doorbell button has a built-in light which is off now. I replaced it with a new button and the new button doesn't light either. That led me to check the voltages at the doorbell unit and it has no power.



I understand that doorbells run at a lower voltage which is achieved via a step-down transformer. My problem is that I can't seem to locate the transformer. I checked at the obvious places (near the furnace, near the fuse box, behind the doorbell chimes) but haven't found it yet. My next option is to trace the wires from the doorbell using an inductive probe.



I obtained a Progressive Electronics Model 700C kit which include the



200EP Inductive Amplifier and Tracer 2 Model 77HP tone generator. Unfortunately I can't locate the instructions to use the unit. I see the Tracer 2 tone generator has two alligator clips (black & red). Do I just connect one (red?) of these to the wire that's supposed to come from the transformer to the door bell, set the switch to "Tone" and then use the inductive probe to follow the wire or do both wires need to be connected?

Appreciate instructions or suggestions you might have. Thx!



:Chet.



Where we are they put them out in the garage, surface mounted on a gang box up high out of reach.

Try removing the doorbell light bulb and see if it works without it.

Check the furnace room. It might be located on a flat plate near the furnace/hot water tank. Most are 10 VAC.

I tried once to located a transformer for a door bell with a toner and probe, and then with a cable locator. I never did find it. One trick I have learned since then is sometimes you can locate a wire of a pair easier if you just connect one lead instead of both. Not sure why, but it works sometimes.

Try connecting one wire of the tone generator to an earth ground.

because if its a closed loop the tone drops out...its how you can tell if you have a short. use the red to one side of the loop you're trying to trace and the black to a good ground and you'll get the best tone. not sure if you can do this with power on the circuit...I forget.

| > I understand that doorbells run at a lower voltage which is achieved | > via a step-down transformer. My problem is that I can't seem to locate | > the transformer. I checked at the obvious places (near the furnace, | > near the fuse box, behind the doorbell chimes) but haven't found it | > yet. My next option is to trace the wires from the doorbell using an | > inductive probe. | >

| > I obtained a Progressive Electronics Model 700C kit which include the | > 200EP Inductive Amplifier and Tracer 2 Model 77HP tone generator. | > Unfortunately I can't locate the instructions to use the unit. I see | > the Tracer 2 tone generator has two alligator clips (black & red). Do I | > just connect one (red?) of these to the wire that's supposed to come | > from the transformer to the door bell, set the switch to "Tone" and | > then use the inductive probe to follow the wire or do both wires need | > to be connected? | >

| > Appreciate instructions or suggestions you might have. Thx! | >

| > :Chet. | | I tried once to located a transformer for a door bell with a toner and | probe, and then with a cable locator. I never did find it. One trick I | have learned since then is sometimes you can locate a wire of a pair easier | if you just connect one lead instead of both. Not sure why, but it works | sometimes. | | | -- | Bob La Londe |

formatting link
| | | |

You might not need to use the tone generator at all. Frequently the doorbell transformer is mounted to the outside of the electrical breaker box (aka "load center"). Sometimes it's mounted to the floor joists near the breaker panel.

I've found more often than not it's the stupid lighted switches...replace with a normal unlighted switch and alls well.

| >

| > | > I understand that doorbells run at a lower voltage which is achieved | > | > via a step-down transformer. My problem is that I can't seem to locate | > | > the transformer. I checked at the obvious places (near the furnace, | > | > near the fuse box, behind the doorbell chimes) but haven't found it | > | > yet. My next option is to trace the wires from the doorbell using an | > | > inductive probe. | > | >

| > | > I obtained a Progressive Electronics Model 700C kit which include the | > | > 200EP Inductive Amplifier and Tracer 2 Model 77HP tone generator. | > | > Unfortunately I can't locate the instructions to use the unit. I see | > | > the Tracer 2 tone generator has two alligator clips (black & red). Do I | > | > just connect one (red?) of these to the wire that's supposed to come | > | > from the transformer to the door bell, set the switch to "Tone" and | > | > then use the inductive probe to follow the wire or do both wires need | > | > to be connected? | > | >

| > | > Appreciate instructions or suggestions you might have. Thx! | > | >

| > | > :Chet. | > | | > | I tried once to located a transformer for a door bell with a toner and | > | probe, and then with a cable locator. I never did find it. One trick I | > | have learned since then is sometimes you can locate a wire of a pair | > easier | > | if you just connect one lead instead of both. Not sure why, but it works | > | sometimes. | > | | > | | > | -- | > | Bob La Londe | > |

formatting link
| > | | > | | > | | > | | >

| |

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required