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Author Topic: Lamp house installation question? Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 05-24-2008 04:53 PM                     An open question I'm interested in getting opinions on. I'm not going to name the site(s) or the installer(s) but I am concerned about the method used and it's safety. However it's not the first time I've seen this method used. The set-up is as follows.... Strong lamphouse (Super lumex can't recall model) requiring 110v ac supply. Irem 3ph rectifier. Step down transformer for UK 220v-110v mounted inside rectifier. My concern is that when power is applied to the rectifier, but it is not actually turned on, there is 110V going to the lamp house electrics, fan, igniter and hour meter. It is therefore possible to press the strike button and attempt to strike the lamp even though there is no DC. In addition the hour meter runs continuously therefore not giving an accurate measure of lamp running life. I cannot understand why the step down transformer was not supplied by the switched ac terminals within the rectifier thereby turning all power of with the control circuit switch. What do you guys think your reaction would be if you came across this at a site you attended? Regards.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-24-2008 05:03 PM                     It sounds half installed. That is, there should be 120V fed to terminals 2 and 4 within the lamphouse. This would indeed turn the blower on (US standard) but it should NOT turn the hour meter on until the On/Off of the lamphouse is turn on and in the manual position or if in the auto position, until the the automation completes the circuit on terminals 3 and 6. You should then have on terminals 5 and 6 of the lamphouse feed a 120V coil relay. Wire the NO terminals of the relay to the first and third terminals in the rectifier (I think they are A and B but I won't swear to that). This will keep the 120 and 230V separated and everything switching as it should. Steve  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 05-24-2008 07:02 PM                        Steve is right. I use that combination a lot (at least 40 installations.) It works perfectly. If wired correctly, it also allows only one source of power for both lamp and rectifier; a safety feature. Louis  |  IP: Logged Michael Moore Expert Film Handler Posts: 188 From: Dover, DE / USA Registered: Jun 2006 posted 05-24-2008 07:53 PM                        I used the same setup for my irem rectifier as well, with the relay. Works great, and keeps everything separated. Mike  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 05-25-2008 07:43 AM                     Thanks for the info guy's. My main concern is the fact that it would be possible to have the igniter attempt to strike while someone was working within the lamp house. I will check it out when I get the chance. I appreciate the info. Regards.  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 05-25-2008 10:09 AM                        That is a very valid concern, and a very dangerous set-up. Steve is right on target with what he said, I would set-up the connections the way he said, or have a qualified tech or electrician come in and wire it the way he said.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-25-2008 10:27 AM                     Note, the Super Lume-X does have safey disconnects in the Door such that the igniter SHOULDN'T be able to ignite with the door open. Now if the installer put the power on 5 and 6 rather than 2 and 4...I'd have to check to see just what is being back-fed. Steve  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 05-25-2008 11:15 AM                     I'll check and correct the wiring when I next get the chance. The staff are aware of my concerns and are not going to do anything inside the lamp house anyway. As I said one of the places I'm talking about is pretty much what Steve said and I think it may be down to the fact that there are two control switches, the original Irem toggle switch AND of course the lamp house switches. They were not instructed to use only the lamp house controls and continue to use the Irem switch. I will remove the Irem switch and then the controls will work correctly. Sean it's not a matter of not knowing what I'm doing rather just getting an opinion of the way the work was done. As for the other site(s) I KNOW they are not wired correctly and there is nothing I'm in a position to do about it. Thanks again for your thoughts. Regards Ken  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 05-25-2008 11:34 AM                        quote: Ken McFall My concern is that when power is applied to the rectifier, but it is not actually turned on, there is 110V going to the lamp house electrics, fan, igniter and hour meter. And on top of any safety concerns, this could lead to the hour meter not giving an accurate reading of how many hours the lamp has actually been lit for. This was an issue at one of the places I worked, and I only found out about it by accident. I rotated the lamp a quarter turn one morning, and noted the hours in the log. I then went through the booth power-up routine, switching the mains power to the rectifier on but not lighting the lamp until 2-3 minutes before show time. When I did come to strike the lamp, I noticed that the hour meter had incremented by an hour. This was a pure fluke - for some reason the previous reading had stuck in my mind and I recognised that it had changed when I came to start the show, and thought that this was funny. I wouldn't be surprised if, over the total lifetime of a lamp, the meter would be suggesting that it had done several tens of hours, if not hundreds, more than it actually had. A colleague realised where the wiring fault was and fixed it, but if it hadn't been for that fluke, neither of us would ever have known that the fault was there.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 05-25-2008 03:33 PM                        Leo: average US cinema; if the meter shows 1000 hours of bulb use; there is about 450 more hours of being "powered up." Louis  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-25-2008 04:24 PM                     One should also check that the hour meter is of the proper frequency of their country...otherwise it will be most inaccurate. Steve  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 05-26-2008 07:05 AM                     Leo... I know who and where you are referring to and it's a bit of a bad habit. You could also add the site where we worked on the install. But as you know trying to raise a concern was always greeted with foul mouth abuse and shouting. You may recall one young guy left in tears. A four screen they did also had the hour meter and ignition circuit powered constantly until I fixed it. I should add there were no door interlocks wired on two either. The rectifiers at that site have all failed, cheap yet ultimatly very expensive switch mode's, and been replaced with T&R's which perform well and are wired correctly. Steve: I'd never given the 50/60hz a thought and it's worth checking as you say. Although in these cases it would give a lower hour life, about 16%, but still a consideration none the less. Regards.  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 05-26-2008 09:50 AM                        quote: Ken McFall Sean it's not a matter of not knowing what I'm doing rather just getting an opinion of the way the work was done. I wasn't trying to en sinuate that I didn't think you knew what you were doing. I just try to be careful with what I post considering other people read this web site who may not be as qualified and I would hate to see someone electrocute themselves because they saw I post where I said to go mess with electrical wiring so I always try to work in that disclaimer. As far as the safety interlocks in the door I wouldn't rely on those, I have seen too many lamp houses where these have been bypassed. I have seen lamp houses where every single safety interlock was bypassed doors, and blowers. I have had to go on emergency calls for a lamp that won't light and had to bypass a door switch, or blower switch temporarily but I always when back in the next day with the proper switch and replaced it.  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 05-26-2008 10:58 AM                     Sean I was not offended in any way so no problem there. Yes, I agree care should be taken so as not to give the inexperienced ideas which could be potentially fatal. One of the sites I was referring to has been properly done and I realise now that the reason it appears to be wrong is that the cinema was using the rectifier to control the lamp house instead of the lamp house controlling the rectifier. I will remove the rectifier switch and that will sort the problem out. I was suffering a mental block. Thanks again for the time taken Regards  |  IP: Logged

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