troubleshooting pool timer with multimeter

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Old 02-28-18, 11:45 AM
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troubleshooting pool timer with multimeter

We have an Intermatic T101P 110V timer. How can I test - using a multimeter - that the timer is getting fed power correctly ?

(I do not understand how to use a multimeter).

There is a ground, A, 1 and 2 line. A is neutral, 1 is hot from the breaker and 2 is hot going to the pump.

I have a multimeter with 2 probes (red and black). There are four places I can plug in the probes and numerous settings on the dial. Where do I insert the probes (in the multimeter) - where do I set the dial - and where do I place the tips of the probes ?

Thanks.
 
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Old 02-28-18, 12:01 PM
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There are many different styles of multimeter -- can you post a picture of yours or a link to it on a website?
 
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Old 02-28-18, 12:12 PM
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It is a Sperry DM-350A multimeter.

The probe ports are A. Omega, COM and V.
The dial settings are V-, V~, A- and Omega.

Thanks
 
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Old 02-28-18, 12:14 PM
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Some picture help....... How-to-insert-pictures
 
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Old 02-28-18, 12:21 PM
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Here you go... (did it work ?)

Name:  multi.jpg
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Last edited by PJmax; 02-28-18 at 01:51 PM. Reason: labeled meter
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Old 02-28-18, 12:46 PM
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The black lead connect to the "COM", the red lead connects to the "V". Use the red 200 setting on the dial when working with less than 200V, use the red 600 setting when working with 200-600V.

When you test the timer, place one probe tip on the ground wire or metal case and one probe on the A, 1 or 2 terminals. Measurements should be about 0V between A and ground; about 120V between 1 and ground; and about 120V between 2 and ground when the timer is on and about 0V when the timer is off.
 
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Old 02-28-18, 12:46 PM
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Assuming you will want to measure 120VAC, put the probes in COM & V. Normally, you would put the red lead in V and the black in COM, however when measuring AC voltage, it doesn't really matter. Set your meter to the red V~ section, and select 200 (your options are 200VAC or 600VAC max voltage). Be sure to insert the test probes and set the meter to the red 200 setting before connecting the probes to any voltage.
 
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Old 02-28-18, 01:01 PM
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Thank you both. We had four new lines run over about 100 ft from the panel to the pool room yesterday. In the morning the sprinkler system worked, Not today. After a couple hourse trying to get the timer once again working the guy said - well you were only paying me to run the new wires - not to get it all to work !!!

So I followed your instructions. btw the pump is 220 and it works fine manually by flipping a switch, but the timer does not cause the pump to work in any setting. The timer is a 110 V device.

So I have the black probe in COM and the red probe in V. The dial is set to 200 red. The readings I just got with the red probe on ground and the black probe on either A, 1 or 2 was 21 point 2. Does that mean that he has our 110 V timer wired for 220 V ? Does that matter ?

He is coming back in an hour to try and figure out why the sprinkler system no longer works...
 
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Old 02-28-18, 01:09 PM
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Went back to the pool room. Set the dial to red 600. Repeated the three readings. Depending on which probe was attached to ground (or the case) I either got all 021's or all 001's.

There is nothing attached to the green ground screw.
 
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Old 02-28-18, 01:40 PM
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You mentioned that the pump is 220V. According to the T101P specifications (https://www.intermatic.com/-/media/i...cifications-EN), the rated input voltage for this timer is 120VAC. You mentioned that the pump is 220VAC. If the input to the timer is 220V, you've likely burned out the timer motor. I believe that the T102P timer is the model that you should use as it's rated for 208-277 volts.
 
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Old 02-28-18, 01:54 PM
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You can use the T101 on a 240v circuit but it is not correct. The neutral would be on A, One of the hot legs would be on line. One of the motor leads would be on load. The second leg of power would connect to the second leg of the 240v pump. Only one of the power leads would be disconnected to the pump when the timer was off.
 
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Old 02-28-18, 01:55 PM
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I appreciate that. we have had the pool pump in place for at least 5 years. We have had the timer in place for at least 3 years.

Perhaps nearly 2 months ago we had a lot of work done in the yard that uncovered buried cables. The work was completed and we closed everything up. A week or so later there was a loud POP in the backyard, most of the fuses were blown and the breakers tripped. Turns out the only thing (after replacing fuses/breakers) was one of the 4 lines going to the pool pump.

There are 3 fuses in the pool room which seem to control the lines coming in. There are a series of switches which power things on/off. One of the switches is what I need to use now to power the pump since the timer no longer works. There must be some way to feed the timer off that switch so that the pump gets 220V and the timer gets 110V. (but that is only what I am hoping - because as I said - this all worked for years until recently).
 
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Old 02-28-18, 02:07 PM
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According to the wiring diagram (Model T101 SPST) that is near the bottom of the spec sheet I referenced, the load (output) side of the timer gets connected to the line (input) side of the timer. In other words, the clock voltage is not separate from the load voltage. Unless someone rewired the timer so that it's not wired as shown in the specification, the timer motor runs off the input voltage, which I presume is 220V in your case.
 
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Old 02-28-18, 02:15 PM
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So then maybe I shouldn't be as upset with the guy who was trying to get it to work yesterday ? Maybe what we were asking him to do is WAY out of the norm ? Trouble is - in the interim we had another electrician (a real electrician) that somehow managed to get our pump working on 220V on three of the four good lines. I don't doubt that he totally disabled the timer - and now yesterday's guy is looking at the diagram inside the timer box and it is misleading him. Do you have the time to tell me in baby talk ?

How does what you are saying affect this diagram ? Or this description ?

T-101 timer 120Volts

T-101 timer for 120 Volt water heaters

T-101 SPST [single-pole single-throw]
Black Hot wire must connect to pole 1.
Neutral must go to pole A
Black to Load goes to pole 2
White to Load goes to pole A
 
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Old 02-28-18, 02:20 PM
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With the T101P timer as the OP referenced.... the neutral is a separate connection.
This is the timer link..... intermatic/timer-controls/mechanical-time-switches/t101p

This is what I think we are dealing with.....
Name:  t101p.JPG
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Old 02-28-18, 02:30 PM
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Hopefully you guys look at these off-the-wall scenarios as opportunities ...

Given your latest image - does that impact the instructions I was given for testing the voltage using my multimeter ? Should I be using a/1 and A/2 and disregard ground ?

Thanks
 
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Old 02-28-18, 02:34 PM
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If it is wired as I have illustrated..... you will measure 120v from A to terminal 1.
When the timer is off..... you will measure 240v from terminal 1 to terminal 2 if the motor is connected.
 
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Old 02-28-18, 02:35 PM
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Here is the diagram I have been going by. This diagram is on the specification document. To my thinking, the input (line) voltage is connected between the Neutral and Line terminals (A & 1). The load (pump) is connected to terminals A & 2.
 
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Old 02-28-18, 02:39 PM
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The OP has stated that there is a 240v pump in use here.

More than likely.... where I've shown the red wire..... is dead and the pump is only being fed 120v currently.
 
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Old 02-28-18, 02:40 PM
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Pete, I agree with what you've said. Personally, I don't feel comfortable using the ground terminal as one side of the 220V line. If someone who didn't know how it was wired (stranger) touched the ground terminal, he would be in for a rude awakening. Personally, I think it would be better to get the correct (220V) timer (model T102) and wire it correctly so that there's no shock hazard.
 
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Old 02-28-18, 02:44 PM
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Not sure what you are looking at. The ground terminal remains as ground. The neutral remains as neutral. But.... only one leg of the 240v is being switched. There is no neutral being sent out to the pump.

Yes... I agree... a 240v timer should be used. However, we are troubleshooting what is currently on site.
 
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Old 02-28-18, 02:53 PM
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No - it is wired for 220. At one point someone thought they were doing us a favor and switched it to 110 but the pool vac hardly worked.
 
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Old 02-28-18, 03:01 PM
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"If it is wired as I have illustrated..... you will measure 120v from A to terminal 1.
When the timer is off..... you will measure 240v from terminal 1 to terminal 2 if the motor is connected."

Revisited the pool room. In either of the scenarios you mention I got zero on the multimeter. BUT - the manual switch outside anything depicted so far is OFF.

My sixth sense is that no-one has made any changes to the timer box since installation years ago. I KNOW people have made changes to that manual switch. At one point someone 'hardwired' that switch to the local 3 fuse fuse-box to get the pump to run at 220V using 3 of the 4 viable wires.

On the timer itself, there are black and white wires going to a and 1 and a single black wire going to 2. I have not opened the switch.
 
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Old 02-28-18, 03:04 PM
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I don't see how we're going to be able to help you further. Although the pump worked as wired..... it is not correct. With handyman wiring.... it can be very hard to diagnose without being there.

If the pump IS running on 240v..... then at some point.... 240v will have to appear at the timer since the timer is breaking one leg of the 240v power.
 
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Old 02-28-18, 03:15 PM
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Thank you all for your help. If there is a bright spot in all this - these Intermatic timers are made in Mexico and cost about half the price they cost in Home Depot US.

When we bought the house the previous owners relied on water temperature to circulate the pool/spa water. It is a cheapo device and we have never used it but the guy who added the timer added it with the direction of leaving that temperature device in place in case someone wanted it it the future.

Again - thanks - I'll pick up a T102 device and have both on hand for a new 'real' electrician to fix this mess. In the mean time I still don't have a working sprinkler system. The guy never showed up...
 
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Old 03-01-18, 05:41 PM
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So today our 'handyman' electrician - who really is a pretty decent jack-of-all-trades person stopped by and connected what he said was a ground wire at the panel box. He said he ran the wire but didn't think he would need it. So tonight - our sprinkler system which wasn't working yesterday is working fine tonight.

Back to the timer - at the end of his visit he and I confirmed that the pump was wired at 220 and the timer was wired at 110. But I had him check the timer with his multimeter and it was registering 75 volts to the timer.
 
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Old 03-01-18, 10:04 PM
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A ground wire should not have any effect on a circuit.
The ground is there only as a safe place for a short to connect.

I don't know what to say about the pump circuit.
 
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