Pattern123 Posted December 8, 2009 Share Posted December 8, 2009 I'm posting this here because it's a bit of a mystery and I wondered if anyone else has come across it. A local am-dram group bought two Robert Juliat Cricket Followspots a couple of years ago, they like them, they are the CP93 Lamp version, but they have a big problem with blowing lamps, some don't even make it through a whole show. There are no faults with either unit, both have been examined and kept on/off at Stage Electrics for a week or so with no issues. But when plugged in at the hall they eat lamps. Best I can think is perhaps a mains issue with the sockets they plug into on the balcony. Has anyone else had similar had similar prob? Link to comment Share on other sites More sharing options...
david.elsbury Posted December 8, 2009 Share Posted December 8, 2009 Get an electrician to come and measure the voltage at the sockets that the spots are plugged into, chances are the voltage is too high. Link to comment Share on other sites More sharing options...
sguy42 Posted December 8, 2009 Share Posted December 8, 2009 I'm posting this here because it's a bit of a mystery and I wondered if anyone else has come across it. A local am-dram group bought two Robert Juliat Cricket Followspots a couple of years ago, they like them, they are the CP93 Lamp version, but they have a big problem with blowing lamps, some don't even make it through a whole show. There are no faults with either unit, both have been examined and kept on/off at Stage Electrics for a week or so with no issues. But when plugged in at the hall they eat lamps. Best I can think is perhaps a mains issue with the sockets they plug into on the balcony. Has anyone else had similar had similar prob? I'd second David on the mains voltage, the other thing to check is the voltage of the lamps. If they are using 230V lamps (and in terms of the regulations that is what we are supplied with +- tolerances) but in practice it can be a lot higher. Our supply here is regularly 252V even under heavy loading we only drop to 249V, if your supply is anything like this you'll need 240V lamps. Shane Link to comment Share on other sites More sharing options...
aidso Posted December 8, 2009 Share Posted December 8, 2009 you arnt touching the glass with your hands when you put the lamp in are you? this causes grease to be left o the lamp which heats up and causes the lamp to fail. Link to comment Share on other sites More sharing options...
Pattern123 Posted December 8, 2009 Author Share Posted December 8, 2009 I arnt doin nuffink! They assure me not, and given what it's cost them so far, I doubt it! Link to comment Share on other sites More sharing options...
adam2 Posted December 8, 2009 Share Posted December 8, 2009 I would second the sugestion to check both the actual mains voltage, and the voltage of the lamps. Although the nominal or declared mains voltage in the UK is now 230 volts, the actual voltage supplied is still 240 volts or more in most places most of the time.Replacement lamps should therefore be 240 volt, but some imported ones are 230, or even worse 220. You dont need an electrician to measure the voltage, Maplin Electronics sell a power and energy monitor very cheaply, this simply needs to be plugged in, and the instructions followed. If your mains voltage is consistantly high, or if you have a large stock of 220/230 volt lamps, then it might be worth never turning the dimmer up more than about 95%. Alternatively the lamps you are useing may be fakes of inferior manufacture, I have certainly found fake lamps resembling a well known make, and I doubt that theatre lamps are exempt from this problem. Link to comment Share on other sites More sharing options...
aidso Posted December 8, 2009 Share Posted December 8, 2009 I would argue the over voltage affect. Any electrical item designed to be sold within the UK must be designed to work within the set tolerance which is 230 -10%(209) +6%(243). Just on a side note. Is the fan running on it?(IIRC the cricket has a fan, I know the Foxie has one) Link to comment Share on other sites More sharing options...
niclights Posted December 9, 2009 Share Posted December 9, 2009 I would argue the over voltage affect. Any electrical item designed to be sold within the UK must be designed to work within the set tolerance which is 230 -10%(209) +6%(243).It was 230 +10/-7% and is now +/-10% (207-253). Works fine in one place but not in another says voltage to me. It is not uncommon to see supplies in the 250's. Link to comment Share on other sites More sharing options...
adam2 Posted December 9, 2009 Share Posted December 9, 2009 Years ago the voltage in the UK was 240 volts, plus or minus 6% Some years ago this was changed to 230 volts plus 10% and minus 6% It was proposed to alter this during 2008 to 230 volts plus or minus 10%, this proposed change has not happened, there appears to be some doubt as to whether it has been canceled or merely postponed. In mainland Europe the voltage is 230 plus 6% and minus 10%It was proposed to alter this to 230 volts plus or minus 10%, but again this has not happened, and it remains at 230 volts plus 6% minus 10% Therefore electrical appliances sold in the EU should be suited for 230 volts, plus or minus 10% in order to allow for use both in the UK (actually 240 volts) and in the rest of Europe (actually 220)Most appliances are fine over this voltage range, but it is not possible to make an incandescent lamp that will give good service over such a range. Theatre lanterns in the UK still need 240 volt lamps, and in the rest of the EU still need 220 volt lamps. Link to comment Share on other sites More sharing options...
Pattern123 Posted December 9, 2009 Author Share Posted December 9, 2009 I know they have had all their lamps via Stage Electrics, who advertise their CP93's thus: "CP93 Lamp suitable for 240Volt operation - 1200Watts with a G22 Base" So perhaps the question should be has anyone else had any issues with CP93's, particularly from Stage Electrics? I guess it is still possible their supply is particularly high at the sockets they use at the back of the hall, or more likely there is some spiking or noise, I have suggested that they check the supply. Link to comment Share on other sites More sharing options...
danjshelton Posted December 9, 2009 Share Posted December 9, 2009 Just on a side note. Is the fan running on it?(IIRC the cricket has a fan, I know the Foxie has one) This could be a factor in the case, as the RJ Cricket has an option when purchasing of "With Fan" and "Without Fan", obviously as RJ sell the unit without the Fan it will run fine (else they wouldn't sell it!) but it could be a contributing factor. We have a couple of Cricket's in our Hire stock, which do have the fan's and have never really had any problems, certainly not lamp related. I would estimate that the unit's have been in stock for 3 - 4 Years and have only had 2, maybe 3 lamps in there lifetime, also bear in mind that these are hired out items (and busy!) which are travelled a lot and potentially put into there flightcases when the lamp is warm (Although I wouldn't we don't know what our hire customer's do with them). Cheers Dan Link to comment Share on other sites More sharing options...
Jivemaster Posted December 9, 2009 Share Posted December 9, 2009 Three things kill filament lamps, over volts, capsule figerprints and burned contacts. If the problem occurs at the venue but not at the repair works then it's most likely to be a high line voltage issue. See what a meter reads on the mains, then see if using a true RMS meter you can put a red line on the dimmer at about 90 - 95% corresponding to 240v. Look carefully at the vent slots and fan dust costs lamp life too! Link to comment Share on other sites More sharing options...
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