supplier bridge rectifier for 10kw ST head

[Clarksonguam]

Does anyone know what to look for and how to order a replacement? I have the data plate off of the generator and it is all legible.

Thanks in advance.

[mbryner]

The excitation field is low amperage.   Almost any bridge rectifier (for 240 VAC and up, not low voltage) will work.

Marcus

[playdiesel]

I have sen this one recomended as one that will work with any ST. Everyone who is into DIY should know Surplus Center

http://www.surpluscenter.com/sort.asp?catname=electric&keyword=EMDR

[Horsepoor]

Take a look at these units for Central Georgia Generator.

http://www.ebay.com/itm/40A-ST-Rectifier-/160608418708?pt=LH_DefaultDomain_0&hash=item256501fb94

A little expensive, but giant heat sink, I have never blow one out yet.

[Ronmar]

That last one is probably overkill:).  I would think a ST-10 would pull less than 10A peak field current.  I think my ST-5 only made around 70V peak field voltage, but that was only on some extreme short transient peaks(it's a real ugly waveform).  The surplus center bridge should work just fine for any ST...  Buy 2, theyre cheap:)

[oiler]

http://www.stationaryengineparts.com/ST-and-STC-Alternator-Spares/

[DanG]

I am not an expert on alternator excitation, nor do I play one on teevee, but I know a little bit about high powered diodes.

Bridge rectifiers usually have 'wishful thinking' ratings.

The listed voltages are 'peak' and we usually measure average or RMS. (240VRMS is 340VPEAK)

Ratings at 25°C ambient temperature <-- massive heat sink attached, 144 sq inch surface area etc. for OEM specs.

Single phase, half wave, 60Hz, Resistive or inductive load <-- full wave ratings less than half advertised from additional °C/Watt junction thermal resistance.

For capacitive load, derate current by 20% <-- I could make something up here but likely function of flow cut-in at higher voltages 0-16V instant vs. 0-1V.

Non-repetitive Peak Forward Surge Current <--- spec for inrush to coils usually, seen as short circuit before magnetism has a chance to build up. Tapping into a primary unrestricted supply can throw surprisingly big amps into inactive circuit. Getting near the limits is inviting problems.

Also - cheap and low-power bridges' junctions are instant-on, true industrial grade designs have a soft-start where conductivity ramps in a controlled progression that avoids a perfect digital square wave pulse that rings coils and circuits pretty harshly mechanically and electrically. Think knocking in a gasoline motor.