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#29916 09/27/03 08:07 PM
Joined: May 2001
Posts: 376
frank Offline OP
I have a high-pressure sodium fixture where the xformer had cracked along the weld and sounded like a bees nest. The new xformer has an option in the diagram for a 40mf capacitor to be field installed. The new part came out of stock and as usual it had been opened and the literature removed. I was wondering what the capacitor is for since it was optional. It’s a S54 xformer and the bulb was also marked S54.I hooked it up and it seems to work fine.I have little experience with these lights but it looks like I'll be doing more.

#29917 09/27/03 08:24 PM
Joined: Oct 2000
Posts: 5,392
frank, try the tec-ref section...a few varieties are diagramed

[Linked Image]

#29918 09/28/03 07:16 PM
Joined: Oct 2000
Posts: 2,722
Broom Pusher and

If the Ballast for the 100 Watt HPS (ANSI S54) is a simple Reactor type, then the (optional) Capacitor is for Power Factor correction only. It will work with or without the Capacitor (connects parallel across the Reactor's Line input leads).

As it is now, the complete setup (Lamp + Ballast) has a "Normal Power Factor" (NPF), which is like 50% P.F.
Adding the Capacitor will improve the "NPF" of 50%, to "High Power Factor" (HPF), being in the ± 80% range.
This will change the apx. 3.1 Ampere draw of the NPF setup (as-is), to somewhere around 1.8 Ampere draw under the HPF setup.

Your Ballast would be a single winding type, with only an input and an output lead (for stand-alone Linear Reactor coil). The Ignitor may, or maynot be intregal (housed within the Ballast for intregal, otherwise it will be a peripheral component).
Lamp would use a Medium Base connection - like a normal A-17/19 120 VAC Incandescent Lamp.

If any of this is different, then disregard the above info and let us know! Like for instance, if the Ballast is similar to the one Sparky has inserted, this would be completely different than the Linear Reactor type Ballast.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
#29919 09/28/03 09:01 PM
Joined: Mar 2001
Posts: 333
Scott, what would be the reason(s) for not using the capacitor and improving the power factor?


[This message has been edited by stamcon (edited 09-28-2003).]

#29920 09/28/03 10:44 PM
Joined: Apr 2002
Posts: 2,527
Minor Aside — The HPS ignitor generally requires a lamp socket that will withstand 4kV impulses between socket terminals.

#29921 09/29/03 11:12 PM
Joined: Oct 2000
Posts: 2,722
Broom Pusher and
Stamcon (Steve);

Scott, what would be the reason(s) for not using the capacitor and improving the power factor?

The one and only reason I can think of would be an initial upfront reduction in cost to buy the Ballast Kit (costs a little less without the Capacitor included with the Ballast kit).

Maybe the thought of Capacitor failure is another issue???

It wouldn't be such a major problem for a few users to have only one or two NPF type HID fixtures (this wouldn't get the PoCo so mad [Linked Image] ), but when many NPF devices are used, the PoCo may respond to the rampant VARs with Penalties to the offending customer (allowing and encouraging the VAR abuse).
The above sillyness is referring to penalties (in the form of $$$ on the power bill), for poor power factor equipment.

On the design side, why would anyone want to setup a lighting system, which runs twice as much in load volt-amps than needed?
Sounds strange to me, but not to someone else.

Wish I had more of a better answer to give, but it appears to be an initial price deal.

<begin greedy thoughts mode>
Also, if you drive twice as much current through the windings, it may produce more heat and cook the windings more prematurely - resulting in more Ballast replacements / more $$$ income for Fixture/Component manufacturers.
<end greedy thoughts mode>

It's the Great Ballast Controversy!!!


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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