Hi Martin

Seems the problem is starting current, this will be several times the run current for a brief period until the lathe gets up to speed. If you have put 15Amp fuse wire across the blown cartridge fuse remember the wire will take up to 32A to rupture, the flash when rupturing will produce a lot of heat so be careful.

You most likely need a dedicated 16A circuit wired to an isolator and motor starter, this way you will have a means of isolation, no-volt protection and with the correct overload fitted protection against motor overload.

Rgds, Emgee

I run my machines with a starter even if they will run off a 13amp plug as it is a lot easier to turn on and off with the protection of a thermal overload relay. In your case 1hp needs a 2.8 to 4.2 amp overload set to around 3.2amps.

They are available from Toolstation amongst others

Martin,

Just a thought. When you start it on the lathe in full working mode, you are adding load to the motor. This, in turn, will make it more difficult for the motor to run up to speed and this will cause the motor to take more current. I don't know this lathe, so this question may be somewhat pointless, but by any chance does the lathe have a clutch? If so, is it fully disengaged when you start the motor as, just as in a car, if it is engaged, then this will increase the load on the motor.

Also, some people who have a lever operated belt tensioner, have been known to use that as a pseudo-clutch.

Finally, a starter won't stop any overload from being passed onto the mains supply. Well, it will, actually, by virtue of causing the starter to trip out and disconnect the power to the motor, but then you could be in an even worse situation where the motor never gets up to speed.

It is my understanding that the purpose of a standard starter incorporating a no-volt release and thermal overload is that the thermal overload is to protect the motor against fire or burnout in the situation where it is stalled. The thermal overload has a short delay in it (bi-metalic strip overwound by a small heating coil) which should be sufficient to allow the high initial starting current to diminish to normal levels without tripping. What this means is that if the thermal overload is sized correctly, it WILL NOT stop the high starting current from being passed back to the mains supply.

I fear that a starter will not cure your problem. Unless, and this something I know very little about, it incorporates some sort of slow or soft start by limiting the amount of initial starting current. Suffice to say that my lathe starter has no such device.

Regards,

Peter G. Shaw

OK, just got the last post and see it was stuck bob weights on the CF switch! that explains it!!

I imagine that it is a 4 pole, 1450 rpm motor, the normal for machinery, can't really give any further help there, but if it by chance it is a 2 pole 2800 rpm motor, what ever you do you will have trouble starting with a load, as the revs go up the torque goes down, double the revs, halve the torque. Ian S C

If you would read Ian's answer (again), you wouldn't have to ask…

Regards, Frank

the number of poles is directly related to the speed, which is a function of the frequency of the supply.. In a full cycle a 2 pole motor will make one revolution per cycle so 50 x 60seconds is 3000 rpm, knock off a bit for various losses and you get an average speed of about 2850 rpm. A 4 pole motor will make 1/2 a revolution per cycle so the speed will be a theoretical 1500 rpm, which usually averages out at about 1440 rpm, the most common speed. If your motor is running at 1440 (check the rating plate on the motor) it is a 4 pole. The rotor moves one pole for every completed cycle of the supply. less the "slip" the formula is 120 x frequency over number of poles. The centrifugal switch switches off the start winding when the motor is up to full speed, if the switch was stuck in the on position it is possible that the start winding is burnt out.

Without seeing the lathe I couldnt tell, but if it is a Brooke Crompton 1 hp single phase the chances are it is a 1440 rpm, and doubling the speed most certainly won't do the lathe any good, and could overspeed and burst the chuck! More poles does not neccasarily mean more torque. Can you send a pic of the IXL lathe, I have had a look on google images, and they mostly look like they need a 2 to 3 hp motor… Do you have the countershaft with the fast and loose pulley as described on this page: http://www.lathes.co.uk/ixl/index.html If you do you should be starting the lathe with the belt on the loose pulley so that the notor gets up to speed before you put load on it. If the centrifugal switch is now working and it still blows fuses there is a fault somewhere, unless it is starting into a load it can't handle. Try starting with the belt on a different speed position. Has this motor worked ok on this lathe before, and the fault has just occured, or has the motor just been fitted?

Phil

Help needed for bench drill motor; I have a Clarke metalworker bench drill that up until today was working ok. this afternoon I went into my man cave to potter on something & when I came to use the bench drill it started buzzing when I switched it on & wouldn't start up properly i.e. wouldn't rotate immediately as it did previously. The only way it starts up is if I give the chuck a helping hand to start rotation then it runs ok. I took the belt off, the motor rotates fine, no rumble on the bearings when switched on, the spindle is as free as it was the other day no binding on that but as soon as the belt is replaced the motor buzzes ( loaded ) & struggles to start without my assistance. I suspect this is the motor telling me 'I'm giving up soon'. Has a winding gone down, is the capacitor defunct… There is no magic smoke & no burning smell… yet! apart from simple wiring up a socket, household stuff, & aware of Ohms Law etc I am totally non compos mentis re electrikery

​Considering the type of drill it is, from MM ( usual disc' ), I suspect it will be cheaper to by a new drill than to buy a new motor or have the motor checked out can anyone offer hope… advice… there are a couple of days left on MM's vat free offer this week so I have to make some decision over the next day or two.

TIA

George.

Don't relish the thought of messing about with capacitor… don't fancy getting a wallop of 500 v… just another thought, do these motors have brushes?

​George.

Edited By mechman48 on 15/07/2017 20:15:39

Which was going to be my question. Easy to check, and could give the symptoms.

EDIT – Super Adept Man answered the question………

Edited By David Standing 1 on 15/07/2017 20:34:41