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Motor start capacitor - value ?
Have acquired an old pedestal drill with a
British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? |
Motor start capacitor - value ?
robert wrote:
Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. |
Motor start capacitor - value ?
On 10 Sep, 14:44, The Natural Philosopher
wrote: robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it *due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? * IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. Go to a company that does motor rewinding as a supplier (Yellow Pages) - and of course they will be able to tell you anyway. Rob |
Motor start capacitor - value ?
John Rumm wrote:
The Natural Philosopher wrote: robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. There seems to be quit a variation. The one on my 1hp dust collector was 100uF: http://www.internode.co.uk/SIP/DSCN5328.JPG bloody eck. Thats biog that is. I did have one lying round on me desk, but it got 'tidied up'. It isn't that critical., Its just to 'nudge' the motor in the right direction. Too small and the motor wont start or may start backwards..that's all. http://www.remco.co.uk/products/capa...stud_mount.htm i'll be buggered everything from 1 to 100uF seems to be available. |
Motor start capacitor - value ?
On 10 Sep, 11:45, robert wrote:
Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it *due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? A 70 watt burner motor takes a 4 microfarad. Multiplying up a 1/4 hp should be about 187 watts so try as a beginning 11 or 12 microfarad. Make sure any cap you try is rated for mains ac. if it helps you could use 3 of the burner motor caps in parallel. I got mine from Farnell Components a few years ago |
Motor start capacitor - value ?
On Sep 10, 9:53*pm, cynic wrote:
On 10 Sep, 11:45, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it *due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? A 70 watt burner motor takes a 4 microfarad. Multiplying up a 1/4 hp should be about 187 watts so try as a beginning 11 or 12 microfarad. Make sure any cap you try is rated for mains ac. if it helps you could use 3 of the burner motor caps in parallel. I got mine from Farnell Components a few years ago IIRC motor caps need to be rated to higher than mains voltage, typ 600v. NT |
Motor start capacitor - value ?
"The Natural Philosopher" wrote in message ... John Rumm wrote: The Natural Philosopher wrote: robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. There seems to be quit a variation. The one on my 1hp dust collector was 100uF: http://www.internode.co.uk/SIP/DSCN5328.JPG bloody eck. Thats biog that is. I did have one lying round on me desk, but it got 'tidied up'. It isn't that critical., Its just to 'nudge' the motor in the right direction. Too small and the motor wont start or may start backwards..that's all. http://www.remco.co.uk/products/capa...stud_mount.htm i'll be buggered everything from 1 to 100uF seems to be available. I would suggest to the OP, that he probably won't go far wrong in choosing a replacement cap of the same size or volume, assuming that the voltage rating is the same of course. It depends on the capacitor construction, it's age, but generally for motor start capacitors, the value and voltage rating determine the size/volume. |
Motor start capacitor - value ?
On 10 Sep, 22:51, "Fredxx" wrote:
"The Natural Philosopher" wrote in ... John Rumm wrote: The Natural Philosopher wrote: robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it *due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? *IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. There seems to be quit a variation. The one on my 1hp dust collector was 100uF: http://www.internode.co.uk/SIP/DSCN5328.JPG bloody eck. Thats biog that is. I did have one lying round on me desk, but it got 'tidied up'. It isn't that critical., Its just to 'nudge' the motor in the right direction. Too small and the motor wont start or may start backwards..that's all. http://www.remco.co.uk/products/capa...pacitors_stud_... i'll be buggered everything from 1 to 100uF seems to be available. I would suggest to the OP, that he probably won't go far wrong in choosing a replacement cap of the same size or volume, assuming that the voltage rating is the same of course. It depends on the capacitor construction, it's age, but generally for motor start capacitors, the value and voltage rating determine the size/volume. Same physical size/volume doesn't apply as modern capacitors are very much smaller for the same capacitance and voltage rating. |
Motor start capacitor - value ?
On Thu, 10 Sep 2009 14:44:09 +0100, The Natural Philosopher wrote:
robert wrote: Any advice on what size capacitor to buy and try ? IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. You'll find these in pre-loved (skip grade) central heating circulators (pumps) -- John Stumbles -- http://yaph.co.uk What do you mean, talking about it isn't oral sex? |
Motor start capacitor - value ?
In message , YAPH
writes On Thu, 10 Sep 2009 14:44:09 +0100, The Natural Philosopher wrote: robert wrote: Any advice on what size capacitor to buy and try ? IIRC about 2.2uF 450V DC or 250v AC is the approved sort of size. For a sport of one horsepower motor thing. You'll find these in pre-loved (skip grade) central heating circulators (pumps) Although the capacitor might well be the reason why the pump is in the skip ... -- geoff |
Motor start capacitor - value ?
On Fri, 11 Sep 2009 20:44:46 +0100, geoff wrote:
Although the capacitor might well be the reason why the pump is in the skip ... But not likely - most pumps I come across (or put in!) skips are either surplus to requirements following a boiler swap or have mechanically siezed up. -- John Stumbles -- http://yaph.co.uk I am neither for nor against apathy |
Motor start capacitor - value ?
In message , YAPH
writes On Fri, 11 Sep 2009 20:44:46 +0100, geoff wrote: Although the capacitor might well be the reason why the pump is in the skip ... But not likely - most pumps I come across (or put in!) skips are either surplus to requirements following a boiler swap or have mechanically siezed up. One might well have thought so except that ... I used to descale pumps (dozens of the buggers) for a couple of service companies - about 20% were fine other than that the 2.2u cap had died so , as I said -- geoff |
Motor start capacitor - value ?
In message , John
Rumm writes geoff wrote: In message , YAPH writes On Fri, 11 Sep 2009 20:44:46 +0100, geoff wrote: Although the capacitor might well be the reason why the pump is in the skip ... But not likely - most pumps I come across (or put in!) skips are either surplus to requirements following a boiler swap or have mechanically siezed up. One might well have thought so except that ... I used to descale pumps (dozens of the buggers) for a couple of service companies - about 20% were fine other than that the 2.2u cap had died You were only seeing the non "I just want of get shot of this unrequired pump" collection though - i.e. ones people wanted but thought needed fixing. Social housing ? I doubt they got any further than ringing up and saying that the heating had stopped working - t'would be the incompetent fitter from the service company who would take it out -- geoff |
Motor start capacitor - value ?
cynic wrote:
On 10 Sep, 11:45, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? A 70 watt burner motor takes a 4 microfarad. Multiplying up a 1/4 hp should be about 187 watts so try as a beginning 11 or 12 microfarad. Make sure any cap you try is rated for mains ac. if it helps you could use 3 of the burner motor caps in parallel. I got mine from Farnell Components a few years ago On the motor on my Myford ML7, (I would think that it's a quarter or third HP) the label says -380W, Cap 75-94 Micro Farad. The actual capacitor label says 75 micro Farad, 275V Hope this helps. Cheers Don |
Motor start capacitor - value ?
On the motor on my Myford ML7, (I would think that it's a quarter or third HP) the label says -380W, Cap 75-94 Micro Farad. The actual capacitor label says 75 micro Farad, 275V Hope this helps. Cheers Don Thanks seems a good starting point. I'm not concerned at getting optimum starting performance. |
Motor start capacitor - value ?
On Thursday, 10 September 2009 11:45:08 UTC+1, robert wrote:
Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? I have one of these motors and it does not appear to have a capacitor on it . It starts but dips the lights in my workshop as it is pulling a few amps on start up is the capacitor internally mounted? |
Motor start capacitor - value ?
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Motor start capacitor - value ?
wrote in message ... On Thursday, 10 September 2009 11:45:08 UTC+1, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? I have one of these motors and it does not appear to have a capacitor on it . It starts but dips the lights in my workshop as it is pulling a few amps on start up is the capacitor internally mounted? There are various designs, some with some with a capacitor, some without. Induction motors inherently have poor starting torque. The ones with a capacitor are marginally better and hence will start against a amall load/run up to speed quicker. |
Motor start capacitor - value ?
In article ,
"harryagain" writes: wrote in message ... On Thursday, 10 September 2009 11:45:08 UTC+1, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? I have one of these motors and it does not appear to have a capacitor on it . It starts but dips the lights in my workshop as it is pulling a few amps on start up is the capacitor internally mounted? There are various designs, some with some with a capacitor, some without. Induction motors inherently have poor starting torque. The ones with a capacitor are marginally better and hence will start against a amall load/run up to speed quicker. Just wondering if the OP knows for sure it's a capacitor-start motor, rather than a capacitor-run motor? The second also gives a higher running torque, but uses higher grade capacitors. -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
Motor start capacitor - value ?
On 08/02/14 09:37, Andrew Gabriel wrote:
In article , "harryagain" writes: wrote in message ... On Thursday, 10 September 2009 11:45:08 UTC+1, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? I have one of these motors and it does not appear to have a capacitor on it . It starts but dips the lights in my workshop as it is pulling a few amps on start up is the capacitor internally mounted? There are various designs, some with some with a capacitor, some without. Induction motors inherently have poor starting torque. The ones with a capacitor are marginally better and hence will start against a amall load/run up to speed quicker. Just wondering if the OP knows for sure it's a capacitor-start motor, rather than a capacitor-run motor? The second also gives a higher running torque, but uses higher grade capacitors. He did say something about a centrifugal switch, which suggests start alone.. -- Ineptocracy (in-ep-toc-ra-cy) €“ a system of government where the least capable to lead are elected by the least capable of producing, and where the members of society least likely to sustain themselves or succeed, are rewarded with goods and services paid for by the confiscated wealth of a diminishing number of producers. |
Motor start capacitor - value ?
In message , The Natural Philosopher
writes On 08/02/14 09:37, Andrew Gabriel wrote: In article , "harryagain" writes: wrote in message ... On Thursday, 10 September 2009 11:45:08 UTC+1, robert wrote: Have acquired an old pedestal drill with a British Houston Thompson single phase 1/4hp motor marked KF TD3205 type BS 2408 The motor start capacitor needs replacing but it has no visible markings on it due to several paint coatings ! With capacitor removed the motor will run with a hand start and I can hear what I assume is a centrifugal switch clicking on spin up and spin down. Any advice on what size capacitor to buy and try ? I have one of these motors and it does not appear to have a capacitor on it . It starts but dips the lights in my workshop as it is pulling a few amps on start up is the capacitor internally mounted? There are various designs, some with some with a capacitor, some without. Induction motors inherently have poor starting torque. The ones with a capacitor are marginally better and hence will start against a amall load/run up to speed quicker. Just wondering if the OP knows for sure it's a capacitor-start motor, rather than a capacitor-run motor? The second also gives a higher running torque, but uses higher grade capacitors. He did say something about a centrifugal switch, which suggests start alone.. Umm.. A centrifugal switch could also indicate a simple split phase motor: where the LR ratio of a secondary winding gives a small phase change and does not require a capacitor. Long while since I actually anything about this:-) -- Tim Lamb |
Motor start capacitor - value ?
In message , Tim Lamb
writes Just wondering if the OP knows for sure it's a capacitor-start motor, rather than a capacitor-run motor? The second also gives a higher running torque, but uses higher grade capacitors. He did say something about a centrifugal switch, which suggests start alone.. Umm.. A centrifugal switch could also indicate a simple split phase motor: where the LR ratio of a secondary winding gives a small phase change and does not require a capacitor. Long while since I actually anything about this:-) Oops! ^^knew -- Tim Lamb |
Motor start capacitor - value ?
I have an ancient table saw with a British Houston Thompson single phase 1.0 hp motor V200-220V. Amp 6.9, RPM 1425, BS170 APPD - the cap is gone and I cant read any values. Any ideas on the cap size??
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Motor start capacitor - value ?
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