Film-Tech Forum ARCHIVE: IREM N3 & G3 series rectifier experiances???

This is topic IREM N3 & G3 series rectifier experiances??? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=007183

Posted by Marin Zorica (Member # 1716) on 05-11-2005, 05:52 PM:

Anyone who worked with IREM rectifiers N3 & G3 series what about them, adventages, disadventages, remote control, heating???

I'm planing to buy one for mine local cinema and i want to know what You think anout it.
I need it for 2500W Xenon bulb.

tnx!

Posted by Ferdinando Innocenti (Member # 2477) on 05-11-2005, 06:01 PM:

So you'd have to buy a N3 100 model. I used a lot of them, the only problems: they are noisy, but you can adjust them to reduce that tremendous sound; sometimes, but these could be mains problems, I have to replace diodes; it happens more often in particular zones or cities, in other no diode fails.

Posted by Mark Gulbrandsen (Member # 72) on 05-11-2005, 07:44 PM:

quote: Ferdinando Innocenti
I have to replace diodes; it happens more often in particular zones or cities, in other no diode fails.

In zones like that all you need to do is to install a properky sized surge protection device on at l4east the main booth panel or better yet on each booth sub panel. This way no over voltage surges will get into your equipment. This is almost mandatory tog et reliable operation with Strong Switching Spplies.

The only thing I don't like on the Irem's is that the ripple level is and always has been just a bit too high. I've measured anywhere frorm 9% to 12% on 2 to 4kw units and this actually exceeds some of Osrams warranty limits. The single phase units have lower ripple by just a tad. Christies rectifiers are typically cleaner at 5 to 7% ripple current.

Still, I like the reliability and convenience of them, the ease of service and one usually gets good lamp life with them.

Mark @ CLACO

Posted by Gordon McLeod (Member # 33) on 05-11-2005, 07:58 PM:

Irem offers a better filter kit if one wants

Posted by Mark Gulbrandsen (Member # 72) on 05-11-2005, 10:01 PM:

Gord,
Does the extra filtration kit offered also include something to control inrush current?

Mark

Posted by Neil Fish (Member # 698) on 05-12-2005, 02:30 PM:

One possible problem with the IREM is low no-load voltage, and can cause problems with some lamphouses that require a higher voltage to trigger the autostrike. Strong Super-Lumex was one type, but Strong produced a retrofit kit that would fix the problem. A zener diode change in the autostrike circuit is the usual fix otherwise.

Posted by Dominic Espinosa (Member # 2122) on 05-12-2005, 03:20 PM:

I don't remember the model off the top of my head but we've got an IREM in our #1 booth. It powers a 45000w lamp beautifully.
Incidentally, it sits on top of part of the original pallet it was delivered on, this deadens much vibration, it's very quiet.
Runs ice cold, though we've got some mejor ventilation running through it.

Posted by Richard Hamilton (Member # 321) on 05-12-2005, 03:47 PM:

I've run into a couple of instances where the no load wasn't enough for a DC ignitor. Both problems were overseas and I believe caused by the incoming voltage to the building. During the day, all was fine, but when all of the lights turned on at night, we had problems. The fix was changing the sidac in the ignitor to a different value. It was looking for 130V, but only getting adout 128V. So I changed them so they now strike at about 110V. No problems since.

The other issue i've had is probably operator error. I have had to replace the plastic coupling block for the current adjustment. Seems they tried turning it too much, and stripped the threads. I recently saw a worker (during the install) just leaning on the Irem and turning the wheel for no reason. Since then I explain to the owner and ask if I should remove the adjustmaent wheel. Especially if the power supply is out in the open, in the booth.

Rick

Posted by Richard May (Member # 2627) on 05-12-2005, 07:50 PM:

Just make sure you take the current adjustment wheel off the top. Operators love to crank them up if it's so easy to do it.

Posted by Gordon McLeod (Member # 33) on 05-12-2005, 11:03 PM:

strong has always provided several different no load voltage boards that were provided on demand with an installation if the engineer specing the system did there homework and specified the right no load voltage

Posted by Richard Hamilton (Member # 321) on 05-12-2005, 11:26 PM:

you mean for the ignitors? I havent heard that. I didnt know that was an option.

I only ran into problems when the incoming power fluctuated. First was because the venue was only operating off a generator. The second was because the load got too heavy when they turned on all of the lights and the heat in the area.

Posted by Mark Gulbrandsen (Member # 72) on 05-12-2005, 11:29 PM:

Years ago I had a similar thng happen except that it was a very slight brown out condition that only happened in the summer because of all the AC's running.

Mark

Posted by Marin Zorica (Member # 1716) on 05-13-2005, 03:54 AM:

Nice to hear You're experiences about that IREM rectifier.
Yes i'm planing to buy N3 100 model, but what about diode fail?
Here i got pretty good mains voltage in both. What kind or type of diodes IREM using?
Also what about Ernemann rectifier, expecialy model X3-110??
Also i can buy ernemann so is it better then irem or??
Anyone had experience?

Ernemann is little bit expensive than irem, but i like them more, are i'm wrong?

Posted by Richard Fowler (Member # 893) on 05-13-2005, 08:44 AM:

The Ernemann is very nice to service in terms of hardware layout. The diode stack is blower cooled and uses larger amperage diodes than IREM. Most IREM are convention cooled and in some situations we have installed muffin fans to keep the diode bank from overheating.

Posted by Dave Macaulay (Member # 813) on 05-13-2005, 11:21 AM:

Irem diodes are a common size however all are reverse polarity; this is not an unusal thing though and they should be easily available from any electronic parts distributor. The diode current rating looks a bit low but the circuit is slightly unusual to North American eyes. Apparently with 6 diodes they are not overloaded even though a single diode's current rating is lower than the rectifier's output current rating.
The heatsink looks too small and has no fan, but it works so who am I to argue? The Strong passive rectifiers have large heatsinks and forced air cooling and still get mighty warm, Irem heatsinks get quite hot but the diodes rarely fail when the unit is clean and the cooling vents unobstructed; with the fans, Strong heatsinks get caked in gunge and overheat rather regularly.
All in all think Irem would be a good choice.

Posted by Louis Bornwasser (Member # 3063) on 05-14-2005, 08:13 PM:

Cannot find a single bad thing to say about IREM's. Some diodes fail; occasionally a contactor fries, 2 RA relays in 35 years have failed. 90% of mine have run for 20+ years without having the covers off. I have about 375 in use.

As for heating, I have several customers running 2000 watt bulbs at 85 amps on 50 amp rectifiers without a problem (Remember I am in a 60 Hz country)(The design on these is 50 Hz and I am certain they run hotter at 50 Hz.)

It is well known that IREM ripple is high; judging by the wonderful bulb life we get, ripple must be GOOD!