Hitachi desk fan capacitor replacement

[Dan Ross]

I found (on web searches) reference to motor "run" capacitors and motor "start" capacitors. Don't know which I need. In the base of the fan, directly from wall cord, this capacitor was removed: MP CON. 2uF 230V.AC (Hitachi logo mark) 808 or 8D8 (looks like "8D8" to me). I live in Japan, but the "home centers" here don't stock electronic parts (& no electronic supply stores in the countryside where I live) and when the home center called Hitachi repair service, the maker claims that the fan is too old and no repair parts are available anymore (of course, the purpose of that is to sell new fans at high price). I replaced a capacitor in a Japanese fan before (someone was throwing the whole fan away as it would only hum, or the fan blades "almost imperceptively" moved slightly when power was switched on). After the capacitor replacement it ran robustly with zero trouble for 3 years and I gave it away to someone later who is probably still using it to this day. So, I thought capacitor replacement would be easy, until I found out the variety that is out there, when searching Amazon's Japan web site. Also, I wonder if replacing the 230V with a 250V would be alright (asssuming I keep the 2uF the same). I found a "ceiling fan" capacitor on US side Amazon and wonder if it might work. It is newer style, black square block, but is rated at 2uf 250V. several others are rated at 2uF 450V. So, Q1: Start or Run capacitor, which is needed?; Q2: If 2uF is kept the same, is 250V or 450V wrokable (and safe) as a replacement? Thank you for your help.

 

[Bluejets]

Old one is probably paper type and your ceiling fan type will be plastic film but both are used in the start winding.
They stay in circuit all the time (no switching) and during startup they help to pull the start winding "out of phase" with respect to the run winding to give the necessary rotational force to get the initial spin happening.
As the start current dies off the start winding then behaves more like a run winding.
Probably made you more confused than ever now but suffice to say, the ceiling fan cap should work ok.
(250vac will be ok ...no need to go to higher voltage but if the former was not available then the 450vac would work just as well)

 

[duke37]

I'm no expert here but the higher the voltage rating the better.
A motor run capacitor is intended to run continuously, a motor start capacitor might object to continuous running.
Size might be a problem with a high voltage capacitor.

 

[Minder]

There are typically two types used, start and run, with the run capacitor being high duty cycle, IOW can be permanently in circuit.
Start capacitor are low duty cycle due to often being bi-polar constructed from two electrolytics back to back, but not used on a small fan.
For a fan I would only expect one capacitor and that would be a run type.
The higher the voltage the better.
M.

 

[Bluejets]

Typical fan motor.

 

[dorke]

You can try this one:
http://www.ebay.com/itm/CBB61-Model...citor-Black-/301686335348?hash=item463de82774

Should be cheaper than Amazon.
It requires soldering (unlike the original),
but will work perfectly and safely.

 

[Dan Ross]

Old one is probably paper type and your ceiling fan type will be plastic film but both are used in the start winding.
They stay in circuit all the time (no switching) and during startup they help to pull the start winding "out of phase" with respect to the run winding to give the necessary rotational force to get the initial spin happening.
As the start current dies off the start winding then behaves more like a run winding.
Probably made you more confused than ever now but suffice to say, the ceiling fan cap should work ok.
(250vac will be ok ...no need to go to higher voltage but if the former was not available then the 450vac would work just as well)

Excellent. I was a bit confused at first reading, but after reading other responses and going back to this it suddenly became clear. Excellent explanation of the start "kick" and then the current dies off and the same capacitor works in "run" (continuously, if that's the right word for it). Also, thank you for the higher voltage being workable. I guess that keeping the 2uF exactly matched is the main point, and not going less than the original voltage (and going higher voltage is fine). Thanks again.

 

[Dan Ross]

There are typically two types used, start and run, with the run capacitor being high duty cycle, IOW can be permanently in circuit.
Start capacitor are low duty cycle due to often being bi-polar constructed from two electrolytics back to back, but not used on a small fan.
For a fan I would only expect one capacitor and that would be a run type.
The higher the voltage the better.
M.

Thanks for the note that only one capacitor is used for a fan. I guess the "start" and "run" types (if both used on the same motor) are only used or needed on large industrial motors. So, the smaller home fan only uses one capacitor (which serves double duty as both "starter" and "run"). Thanks.

 

[Dan Ross]

You can try this one:
http://www.ebay.com/itm/CBB61-Model...citor-Black-/301686335348?hash=item463de82774

Should be cheaper than Amazon.
It requires soldering (unlike the original),
but will work perfectly and safely.

Thanks for this link. That looks like a capacitor I ran across on the web somewhere (maybe on US side Amazon), but the eBAY link has worldwide shipping which I need for Japan. Sometimes Japan Amazon does not list or offer certain items shown on the US Amazon site which makes shipping to Japan unavailable at times. Thanks for the link and info that higher voltage will work (from several of the posters here).

 

[Dan Ross]

You can try this one:
http://www.ebay.com/itm/CBB61-Model...citor-Black-/301686335348?hash=item463de82774

Should be cheaper than Amazon.
It requires soldering (unlike the original),
but will work perfectly and safely.

I found an electronics shop in Sendai called "Marutsu" and found a similar square block. 2uF 250V. It had solder terminals rather than wires coming out of it, and it worked like a charm. The fan is back in working order now and runs beautifully. Thank you to all for your great posts here.

 

[dorke]

Nice to hear