Allen Bradley Legacy Contactor

Reply

  #1  
Old 04-11-08, 11:47 AM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
Allen Bradley Legacy Contactor

This my first time at your forum and I was wondering if anyone has experience with Allen Bradley contactor wiring? I have a compressor with a 240v 3hp motor and an old Allen Bradley 700 Series motor control/contactor (709-cod 103 Size 2) with overload relays and a coil. I get power to the enclosure and to the compressor side of the fuses. I cannot get the coil to engage. I acquired this unit and the coil was not wired-up. Through hours of internet searching I saw an example of a 702 cod93 wiring, tried it and it didn't work. Can anyone suggest how to test the coil to determine if it is working and/or how to wire the coil. I have picts. but don't see a way to upload them here. Thanks, Dmend
 
Sponsored Links
  #2  
Old 04-11-08, 12:11 PM
Member
Join Date: Oct 2005
Location: USA
Posts: 1,451
Received 15 Votes on 15 Posts
verify push button on and off?

Also, you can easily measure coil ohms with a DMM; power off first, of course.
 
  #3  
Old 04-11-08, 01:00 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Received 0 Votes on 0 Posts
the 709 series contractor that i havent see for quite a while but however if you want to upload the photo go to the Photobucket website or other website that can host the photo and from there you can upload it with link or paste the photo but however you may want to hang on a sec.,, i will let other memebers who have experince with this how to upload the photo in safe way.


however let get back to the topic for a min.,,

if the coil look very clean you should able read the voltage rating on the coil

is the contractor is single or three phase verison ??

i will dig up a diagram for common air compressor in little while

Merci,Marc
 
  #4  
Old 04-11-08, 03:18 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
Here are three photos.



My motor does not use a ground so there are only T1 and T2 going to the control unit.
The red wire connected to the coil was originally connected to the mounting screw of the coil, I moved it based on a photo I found. The other red wires beneath the overload relays are as when I received the unit.



The transformer on the right has a fuse mounted underneath it. The red wire on the left feeds from behind the unit. I can't say it is actually connected to anything. The red wired on the right of the fuse originally was cut and missing. I tied it to the Off-hand-Auto switch.
Coil is 12v 60HZ part no. 72a86.
The previous owner never used the unit as it was intended, but said it did work when he obtained it.







Ideally I'd like to get this wired so I can use the Off-hand-Auto switch, which I believe will be wired to the compressor pressure switch. But, first the main wiring.

Thanks,
dmend
 
  #5  
Old 04-11-08, 09:34 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Received 0 Votes on 0 Posts
Sorry for the delay here but however i have few instering question rasied up now and i have few condsering to ask you few things

1] control transfomer do you see the marking or label somewhere ?? if not i will not try to hook that up because without the label on the control transfomer they can be wired at much higher voltage either 240 volts or 480 volts [ common voltage used commercal / industrail useage ]

2] the starter size which i do relized now that is really pretty big starter you got there that is a size 2 starter

you qouted that you got 3 HP motor at 240 volts is that is single or three phase motor ?? i just want to make sure i can see all the facts here before i can comment on that.

3] the heater strips [ overload element ] i need to know what the number stamped there so i can able help you to dail in more closer to the size of the motor you got there.

normally with the contractor with 3 HP motor [ single phase useally use size #1 sometime size #1 1/2 ]

Merci,Marc
 
  #6  
Old 04-11-08, 09:54 PM
nap's Avatar
nap
nap is offline
New Member
Join Date: May 2006
Location: north
Posts: 4,163
Received 1 Vote on 1 Post
from what I could see, in the first pic, you do not have a neutral wire connected to the coil terminals (which I can see is a 120 volt coil). In the second pic I can see a wire on that very terminal ( a red one). If you connected 240 volts to the coil, you may have already smoked it. An ohm reading is not very definitive as a coil such as this will have a very low reading. If some of the windings have shorted together, it may not be a readable difference.

So, based upon what I see, you do need another wire to the starter; a neutral for the contactor coil.

whoops, missed the transformer. I would think that is a 240 to 120 volt transformer but youneed to verify. If it is, you get your control power from the secondary side of that transformer, both the hot and the neutral.
 
  #7  
Old 04-12-08, 02:58 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
Here is the transformer info.:

Primary voltage:Secondary voltage:
240/480 220/440
120 110
Hertz:
60 50/60
K.V.A. .075
 
  #8  
Old 04-12-08, 03:20 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,064
Received 19 Votes on 19 Posts
You have a three phase contactor there.
Are you using this on a 220 volt single phase motor?

It looks like the transformer and hand/off/auto switch is already wired up.
You should first make sure the transformer primary is connected to the 240 volt tap.
After you make sure the transformer is connected to the 240 volt tap, follow the wires from the transformer and make sure they are connected to the hot side of the contactor and on the same two lugs as the 220 volt incoming line.
It should be powered continuously on the Line terminals.

This is a single phase motor right?

You also have to do away with the hand/off/on switch or do away with the hand function.
It is not appropriate to bypass the pressure control on a compressor.
 
  #9  
Old 04-12-08, 03:24 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
I dropped the overload relays and the only info. on them is CBM, on the bottom.
Also, the fuse on the transformer is tied to the neutral overload relay.

Based on what you've described I can install a wire from the neutral overload relay to the pole on the right side of the relay, opposite the red wire as in picture #1. I don't know if I smoked the coil, never saw or smelled smoke, but I suppose that is not a definitive indicator.

Do you think anything needs connecting to poles numbered 2 and 3 on the coil?

I have no experience with transformers, can you be more specific on what goes where?

dmend
 
  #10  
Old 04-12-08, 03:47 PM
nap's Avatar
nap
nap is offline
New Member
Join Date: May 2006
Location: north
Posts: 4,163
Received 1 Vote on 1 Post
I'll get back with some other info but for the moment, to test the coil. disconnect any wires from it and then take a 120 volt power source (the hot and neut) and attach the neut to one of the terminals and the hot (not turned on) to the other terminal.

then using the breaker for the circuit or some other control in the circuit, energize the coil. If it does not pull in instantly, turn it off, the coil is bad. If it pulls in, the coil is good (or most likey. I have had coils that are bad but only show up after heated up) so turn the power off and disconnect the temp power.
 
  #11  
Old 04-12-08, 03:47 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
I've run this motor as 220V single phase. There are other wiring configurations available, its been a while since I've had that cover off the unit.

The transformer is not connected to anything. In pict. 2
the black wire on top is jumped to another pole just to the right of it. There are two more poles, one behind each of the front poles.

I wasn't sure how "Hand" on the switch would come into play. I agree, Off or Auto are the only two options.

So, for the Off/Auto switch wiring to the air pressure switch: one wire connects to one of the 110V powered terminals (Tapped off the overload relay?) to the Off/Auto switch to one pole on the pressure switch. Then, from the other pole on the pressure switch to the fuse which ties to the neutral overload relay. Is that correct?

dmend
 
  #12  
Old 04-12-08, 04:07 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
The coil test shows it to be good.
 
  #13  
Old 04-12-08, 04:34 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
I forgot about the name plate on the motor, DUH. It is single phase.
dmend
 
  #14  
Old 04-12-08, 05:39 PM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 10,064
Received 19 Votes on 19 Posts
You would first need to connect the primary of the transformer to the hot leads on the contactor so that it is powered continuously and correctly configured for 220 volts.

Can't tell by the picture but the fuse is likely in series with the 120 volt cct.

You would then feed the switch from one leg of the 120 volts and then connect the other side of the switch to one side of the heater control, out the heater control to the pressure control then out of the pressure control to the contactor coil.
The other side of the contactor coil gets connected to the other leg of the transformer secondary.

You would need to let us know what numbers are on the contactor heaters and the fla of the motor.
There is often a chart on the inside cover of the contactor that indicates the amperage rating.
 

Last edited by GregH; 04-12-08 at 08:12 PM. Reason: Thanks nap, must have been napping!
  #15  
Old 04-12-08, 07:37 PM
nap's Avatar
nap
nap is offline
New Member
Join Date: May 2006
Location: north
Posts: 4,163
Received 1 Vote on 1 Post
Greg, you forgot to run through the pressure switch and you definately need the control power to run through a contact controlled by the overload section of the contactor.
 
  #16  
Old 04-12-08, 07:38 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
The fuse is in series, connected to the T3 heater. However, currently there is a jumper from T1 to T2 and a jumper from T2 to T3 heaters, though not really visible in the pictures. That looks weird to me. Should those be removed?

Also, although this contactor is 3 phase I've got T1 and T2 hot and T3 as ground, so the fuse is connected to ground/T3.

The motor plate shows 17.7amps/208V and 16.5amps for 230V. I was told by the previous owner that he motor is a replacement so it may not match the heaters that are probably original and which most likely used as 3 phase. And, I was told that the motor pulls down 17 amps when the compressor is pumping 0-50psi, and 21 amps at 50-100psi.

There is a chart in the cover for the heaters. Shows size 0, size 1, size 2. They all show N37 as the heater type nearest to 17.7amps. If the above 21 amps is relevant then size 1 N39 and size 2 N38 is recommended. There are no numbers on the heaters and we don't know the original motor size. Are we in pickle barrel?


Here is a better picture of the transformer. Are the two poles in the front and jumped together the primary, thus the back two the secondary?
Question: if the transformer is continuously running is it drawing power if there is no load on it? If it does then I expect to throw the enclosure lever to off when not in use.


I realize this is taking alot of time and so very much appreciate you patience. The mrs. is home now, gotta end for tonight. dmend
 
  #17  
Old 04-12-08, 10:43 PM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Received 0 Votes on 0 Posts
here the photo of connection diagram



however there is one change you will have to deverted from the diagram for the air compressor useage you will have to change the connection from 3 wire to 2 wire setup it is very easy to do this if you follow the instruction verycarefully.

you see the drawing there where the start and stop connection is ?? ok disagree with that connecton with that one what you do you run the hot conductor from control transformer [ you will see the left fuse on the diagram above ] that is hot lead run that to the HOA [ Hand - Off -Auto ] switch but however you will have to ring one of the two lead you need [ the third one you dont need it due you will use this as on - off function { remark it so you know it is on and off function } one lead from HOA switch to the pressure switch then take the second wire from pressure switch go to the #3 spot connection hook that up don't use the #2 connection but but before you get too far with it.,,,,,,
dont mess around with the overload relay just change the heater to match the motor amparage.


but however you mention 21 amp at 50-100 PSI and the motor rated at 16.5 amp that is little too much for the motor to take it [ it will get hot and overheat it ]

and the other catch is you have to watch out some motor do have thermal overload switch build in. if this motor do not have thermal overload switch or reset switch there then you must use the heater to prevent burn up the motor and you may i say may have to change motor pully [ go smaller diameter ] useally clear up the curpit.

before you do anything more make sure you read the wiring diagram very carefully take a peice a paper and copy this and make a change on the paper and draw the line as i described above for the change.

dont do any actual hook up until you see your diagram show more clear for safety issue.

i am sure you will ask us few more question please do ask us here .

Merci,Marc
 
  #18  
Old 04-13-08, 07:44 AM
nap's Avatar
nap
nap is offline
New Member
Join Date: May 2006
Location: north
Posts: 4,163
Received 1 Vote on 1 Post
let me throw another thing in the works here.

when using a 3Φ starter for a single phase load, there is a proper manner for routing the power through all 3 overloads. I can rarely find diagrams of this stuff. Does anybody have one?

dmend; I just want to be sure about something. There are 6 terminals on the top of this starter, correct?

the 3 in the front that we see that have the hard wire connection to the overloads and 3 behind those that have the line feed power connected to, right?
 
  #19  
Old 04-13-08, 11:55 AM
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,808
Received 0 Votes on 0 Posts
Nap.,, i am glad you speak up on that one but however with the thermal overloads on 1 supply with 3 contractor and O/L's you only need two of three but however here a catch with electronic O/L the bet is off you need to loop from T2 to L3 out on T3 the reason why the electronic O/L do sense current on each mini doughnuts and one of the loop do not show current it will sense single phaseing and it will shut down withen 3~5 seconds.


and let me add this most O/L's do have slection of auto or manual reseting if appacationable if so leave it on manual mode due safety issue with air commpressor.

Nap also let me add this to you with older Allen Bradely contractors.,,

Yes it is correct arrangement by looking top 6 lugs the front three is factory wired to the O/L's while back three is your line connection.

Merci, Marc
 
  #20  
Old 04-13-08, 12:55 PM
nap's Avatar
nap
nap is offline
New Member
Join Date: May 2006
Location: north
Posts: 4,163
Received 1 Vote on 1 Post
here a catch with electronic O/L the bet is off
thanks. for some reason I remember seeeing it on a thermal O/L but couldn't figure out why. Still not sure.



Yes it is correct arrangement by looking top 6 lugs the front three is factory wired to the O/L's while back three is your line connection.
I was pretty sure of this. OP's statements about several jumpers made me want to make sure I was correct and hopefully the OP will explain all the jumpers he spoke of. Something sounds odd but it may simply be my understanding (or misunderstanding) of how he phrased things.
 
  #21  
Old 04-13-08, 05:08 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
Yes, there are three connectors hard wired to the O/Ls. Those are the three you clearly see in the picture. Behind them are the connectors for the 3 lines coming into the contactor from the fuses.

The 21 amps may be an issue. I did run this during a 4 hour sandblasting project. It didn't run continuously so it probably never got a chance to really heat-up. With the correct wiring and a new pressure switch I may get different results. Guess I'll budget-in a potential new motor.

I have my work cut out for me. I'll report my accomplishments later this week.

Thanks again.
No job is so important that it can't be done safely.
dmend
 
  #22  
Old 04-16-08, 09:15 PM
Member
Thread Starter
Join Date: Apr 2006
Location: usa
Posts: 17
Received 0 Votes on 0 Posts
Lets see if I interpreted your instructions correctly. I have not gone live with this.
I thought you should confirm if it is correct.



Here is what I did:
1. Wired Line 1 to transformer primary (poles on the top. This transformer has 4 poles on the top, which I presume are all primaries.)
2. Wired Line 2 to transformer primary (pole on top)
3. Removed the fuse that was attached to the bottom of the transformer and found the secondaries.
4. Wired one transformer secondary to the Off/auto switch. Then, from the other switch pole wired to the #3 on the contactor.
5. Wired #3 to the right side of the coil.
6. Wired the other transformer secondary to the T1 Overload relay.
7. From the T1 Overload relay wired to the left side of the coil.

Questions: The coil wiring looks odd to me. The coil is 120v, shouldn't it need a hot wire 120v and a neutral wire as when I tested the coil. Is this correct to have two 120V lines (220V) on the coil?

Regarding the Overload relays, the original wiring is T1 is jumped to T2 which is jumped to T3. If I understand this configuration, as a 3 phase set-up if either OL heats up it trips them all.

As a single phase 220V configuration should I disconnect the jumper from T2 to T3? Not being used or if T3 being a neutral line if installed.

Thanks,
dmend
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: