60hz motor running on 50hz - UK Vintage Radio Repair and Restoration Discussion Forum

vinrads · 7th May 2019, 6:24 pm

I am it the process of restoring a Philco radio with Mystery control that is a radio remote control . The problem I have the motor has very little toque ,the motor has four windings two in series the enables the motor to be reversed the windings read the same resistance , the applied voltage is correct at 28v . I find this strange as I have restored loads of motors from American Jukeboxes with no problem. any ideas! Mick.

G0HFCFrank · 7th May 2019, 8:59 pm

Hi Mick, I once worked for a firm installing American equipment in UK and the 60hz motors ran fine on 50hz, just 18% slower. I take it your motor has two pairs of coils, each pair wired in series? When you say very little torque is the motor off load and does the spindle spin easily? (A gearbox full of hardened grease will absorb a lot of torque). I guess reversing the supply to one pair of coils reverses the motor? Is there dirty switchgear putting resistance in the circuit? are both coil pairs wired in phase? Please come back with more information. Frank C.

vinrads · 7th May 2019, 11:28 pm

Hi Frank thank's for the reply, the motor spindle runs free , I noticed that when power is applied it just tends to buzz hardly turns at all ,both ways , As I said the resistance reads the same on each coil, also checked the inductance the coils all read the same , even tried some extra volts ,no difference . Mick.

DangerMan · 7th May 2019, 11:48 pm

Is there a motor run (phase shift) capacitor associated with the different windings?
If there is it might be faulty - and in any case should probably be slightly increased in capacitance for use on 50Hz without loss of torque.
Pete

vinrads · 8th May 2019, 7:57 am

Thank's for that Pete , there are some capacitors in the motor cct , I found a 3mf o/c replaced no joy still the same ,there are two other capacitors ,did check for leakage ,I think I need to replace these ,Mick.

vinrads · 11th May 2019, 7:26 am

Problem solved ,the what looked like in the cct a three micro farad turned out to be a thirty micro farad, a new bi polar one cured the problem .I was very pleased it wasn't the motor at fault phew! Mick.

7th May 2019, 6:24 pm	#1
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,762	60hz motor running on 50hz I am it the process of restoring a Philco radio with Mystery control that is a radio remote control . The problem I have the motor has very little toque ,the motor has four windings two in series the enables the motor to be reversed the windings read the same resistance , the applied voltage is correct at 28v . I find this strange as I have restored loads of motors from American Jukeboxes with no problem. any ideas! Mick.

7th May 2019, 8:59 pm	#2
G0HFCFrank Pentode Join Date: Oct 2011 Location: Oldham, Greater Manchester, UK. Posts: 167	Re: 60hz motor running on 50hz Hi Mick, I once worked for a firm installing American equipment in UK and the 60hz motors ran fine on 50hz, just 18% slower. I take it your motor has two pairs of coils, each pair wired in series? When you say very little torque is the motor off load and does the spindle spin easily? (A gearbox full of hardened grease will absorb a lot of torque). I guess reversing the supply to one pair of coils reverses the motor? Is there dirty switchgear putting resistance in the circuit? are both coil pairs wired in phase? Please come back with more information. Frank C.

7th May 2019, 11:28 pm	#3
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,762	Re: 60hz motor running on 50hz Hi Frank thank's for the reply, the motor spindle runs free , I noticed that when power is applied it just tends to buzz hardly turns at all ,both ways , As I said the resistance reads the same on each coil, also checked the inductance the coils all read the same , even tried some extra volts ,no difference . Mick.

7th May 2019, 11:48 pm	#4
DangerMan Heptode Join Date: Jul 2009 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 719	Re: 60hz motor running on 50hz Is there a motor run (phase shift) capacitor associated with the different windings? If there is it might be faulty - and in any case should probably be slightly increased in capacitance for use on 50Hz without loss of torque. Pete

8th May 2019, 7:57 am	#5
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,762	Re: 60hz motor running on 50hz Thank's for that Pete , there are some capacitors in the motor cct , I found a 3mf o/c replaced no joy still the same ,there are two other capacitors ,did check for leakage ,I think I need to replace these ,Mick.

11th May 2019, 7:26 am	#6
vinrads Dekatron Join Date: Feb 2009 Location: Chesterfield, Derbyshire, UK. Posts: 3,762	Re: 60hz motor running on 50hz Problem solved ,the what looked like in the cct a three micro farad turned out to be a thirty micro farad, a new bi polar one cured the problem .I was very pleased it wasn't the motor at fault phew! Mick.