Robe Spot 150XT problem

[KevinE]

Hello, wonder if anyone's come across this one.

 

We've got two Robe Spot150XT moving heads with identical problems. After half an hour use, the lamp turns off, waits 5 mins then turns on again, works 5 mins, turns off, and so on.

 

I stripped them down, discovered the lamp cooling fans were open circuit. I replaced them (identical Sunon units) and tried again. Same problem! So I changed the lamps - Philips CDM S/A-T150 . But the same problem! I've ruled out a loom fault as they both work half an hour from cold then cycle when warm. There's no DMX lamp control, they're straight off the mains, and they fail if they're moved or just static. The cycling time is pretty consistent. They cycle within 10 mins of each other but not synchronised.

 

I wondered if maybe anyone had had a similar problem, maybe the ballast? I dont know.

 

Cheers

 

Kevin

[3guk]

We had some of these on our bench the other week, will ask the guy who was working on them on Monday for you, pretty sure they had the same fault as detailed.

 

We managed to narrow it down, by leaving them outside and seeing how long the lamps took to turn off, and surprise surprise they lasted much longer. Fairly sure one of the boards had a fault with it.

 

Might be worth speaking to Robe about it, the tech guys are superb, and can usually tell you what is wrong pretty much instantly.

[KevinE]

Yep I might well do, the venue are limping on with them at the mo so I need to be forearmed as much as possible before taking them out and away for a while! It's unlikely to be a board fault as the boards don't switch the lamps on this model, the lamp circuit is straight across the mains and the fans run continuously / correctly.

[Guest joewhite903]

Which XT's are they ive got the schimatics for them, it sounds like the thermal trip kicking in (90degre c) mounted above the ignitor, try cleanning all around that area and try replacing it with one of the same kind. Joe

 

thermo part number for the 150xt (scan and roller) 13050052

[KevinE]

They are the Robe Spot150XT. I did suspect the overtemp stats, maybe gone weak with the original cycling bout due to the open fans. They certainly aren't overheating (as such) and of course they were cleaned to within an inch of their life when I replaced the fans.

 

Of course the stats may themselves not be cycling but merely 'blipping' open when warm, as thats all thats needed to extinguish the hot-restrike lamp until it's cooled enough to restrike. (There's no lamp strike fail error facility either in these units.)

 

You say they're 90deg? I might swap them. Can you remember if they're riveted or screwed in place?

[Guest joewhite903]

The spot 150 takes a 100C thermo (13050225) unlike the 90C in the scans and Is held into place with 2 screws on the side of the lamp frame , also have you replaced the micro fan 40mm-40mm beside the thermo. Ta joe

[KevinE]

I havent replaced the other fans but they're ok.

[johnhuson]

Sounds like a faulty thermal cut out to me.

[craiguss]

did you ever fix this problem?

I have the same!

 

thanks,

[KevinE]

Yes; sort of. I attached a temperature probe to the lamp house and ran the lights up with the covers all in place. With the fixtures moving, the temperature stayed below 70; but if they were left 'parked' with the fan grille on top, the temperature rose to over 90 after half an hour. I considered this too close to the knuckle for a 100deg cut-out and so I changed the old Sunon fans for Papst ones with a slightly higher output..the result was a consistent 45deg internal temperature all night. They haven't gone wrong since.

 

PS A more serious fault that can cause lamp cycling (and eventually failure) on these fixtures is a worn lamp cable where it passes through the pan bearing...I think I already posted a pic of this on BR a few years ago.