photys 0 Posted July 31, 2007 Was called in to add five cameras to an existing system. The in-house electrician available to me missed every meeting over a 4 week period. After one too many excuses, I took the advice of the original installers and 2 different electricians. The existing eight 12Volt cams were running off a 13.8Volt 7Amp power pack. Both the electricians and original installers crunched the numbers and said "plug em in, your fine" Seems the voltage loss was minimal and that extra voltage fried the cameras. So im sat here with the deposit spent, no final payment and only myself to blame :/ Share this post Link to post Share on other sites
scorpion 0 Posted July 31, 2007 I am confused! What voltage were the cameras rated at? The extra voltage fried them? 13.8 volts? Sounds like to me you had a short somewhere! Was this a boxed power supply? I would have hoped that the fuses would have isolated that particular "circuit". If it was not a boxed power supply what kind was it? How were all of the power wires attached? Do you have emails where they told you that you can "plug them in you are fine"? Do you have it in writing? You don't? If you did you could make them pay for the new Proper power supply, and your added labor to boot! I really feel for you man! I guess it's a monday after all! Share this post Link to post Share on other sites
photys 0 Posted July 31, 2007 I´m guessing the extra voltage and this heat wave killed em :/ Still cant get the electrician........ Standard European 12 volt bullet cams. Boxed 13.8 volt, 7 amp power supply with + and - screw on terminals to add however many wires you have. 7 Amp version of this http://www.skytronic.co.uk/product/product.php?s=650.651 Wires were crimped onto a terminator and screwed on. No emails, nothing written. Tested the end of the cable and its getting 13.6 volts...... Over the +/- 10% the cameras are rated for. Just found out three cameras have gone down in the past two years, the electrician checked the system and signed off on it. Maybe thats why he was dodging the meetings :/ The event log shows the cameras dropping one at a time over a 40 minute period. Dumb dumb dumb...... dont listen to an electrician, make them sign off on the work before you plug anything in. Whichever way I look at it, i´m biting these bullets! HA! ..... first time I´ve smiled all day ) Share this post Link to post Share on other sites
rory 0 Posted July 31, 2007 Dont feel bad. .. i think I just fried a Sanyo Day Night Vandal Dome the other day when I hooked up 12VDC and it was setup previously for 24VAC .. didnt get any video but had to leave the location so wont know until tomorrow or the next day .. kind of sucks as that was a nice camera .. if it is fried that is .. i could have just loosed the video cable from inside the camera by mistake when I was messing with it, Im hoping that is it Share this post Link to post Share on other sites
survtech 0 Posted July 31, 2007 (edited) I had the same problem with an expensive Dallmeier casino cam. It's rated at 12VDC at (I didn't notice the small print) +/- 5%. That means 11.4-12.6 volts. It actually smoked!!! I don't know how they expect us to maintain 5% voltage tolerance in the field. But then again, I often wonder what is wrong with engineers in general. They have no concept of how things work in the real world. I questioned them and they agreed that the tolerance was that close. Stupid!!! 13.8VDC is the nominal voltage of a fully charged car battery and, at least with some manufacturers, has no relationship to the 12VDC that cameras require. Camera manufacturers could eliminate a lot of problems with a few inexpensive parts. A full wave rectifier bridge and a simple voltage regulator not only can allow the same power connector to serve both AC and DC, it can allow DC to be hooked up without regard to polarity. Edited July 31, 2007 by Guest Share this post Link to post Share on other sites
rory 0 Posted July 31, 2007 Yeah I like the GE because they typically accept either or, plus do 10-30volts. Share this post Link to post Share on other sites
scorpion 0 Posted July 31, 2007 When you measured the 13.8 volts was that under load with working cameras? I know you know not to measure straight off the power supply, I am only asking for those who may read this post, and do not understand that you have to measure the power with everything hooked up to it for it to be a good voltage measure! I do not think that a 13.8 volt 7 amp power supply will kill your cameras!!! The other question is why the protection circuit did not save the cameras? I think the power supply is bad. I think that once it heats up it injects AC in to the supply line. It could be that the rectifiers collapse when hot. It could be that there is a higher voltage then 13.8 and the regulator keeps it at 13.8, and then when it gets hot the regulator collapses, allowing the full voltage value to run straight through to the cameras. I am only guessing as I have never used this power supply. I would do the following: Replace the power supply. Use a fuse block. Check the wiring for possible shorts, or bad connectors. _____________________________________________________ Do you have a proposal where you recommended a power supply, or a different circuit then what they have. I am hoping that they turned down your proposal, and you can use this to get back at them. You can tell them "I told you so"! I hope it works out! Share this post Link to post Share on other sites
photys 0 Posted July 31, 2007 If the voltage didnt fry them, what else could do it? If they shorted out, would I still get a voltage reading on the camera end of the wire? Bear in mind the original 8 cameras on the same circuit were still running. I just guessed that the new cameras were more sensitive to the extra Volts that the original cameras. Scorpion: 13.5 / 13.6 under load, measured at the camera end, after the cameras fried. I remember your post some time ago mentioning your home made tester. I carefully stripped one of the cams and discovered a half burt "quality control" paper sticker! If I lived in the US i would be lawyered-up by now Gotta take a picture if that and make it my board signature! Share this post Link to post Share on other sites
scorpion 0 Posted July 31, 2007 I commend you for doing an autopsy!!!!!!!!! You must be a member of the MENSA! Alot of techs out there would have not gone through the trouble! I have to say I am impressed! If you ever move to Florida, look me up!!! Share this post Link to post Share on other sites
scorpion 0 Posted July 31, 2007 I am curious as to why you would have 13.5 ~ under load? If you disconnected all of the cameras what would be the "unloaded" voltage reading? Now I am really curious! Share this post Link to post Share on other sites
scorpion 0 Posted July 31, 2007 What kind of cameras were they? Remind me to avoid them! Share this post Link to post Share on other sites
photys 0 Posted July 31, 2007 (edited) 13.80 at power supply. 13.55 under load at faulty camera 13.55 under load at working camera. If I get the opportunity, I will test with all cameras disconnected. I was surprised as the reason the original installer put the 13.8 volt power supply in was that there were some 30m to 40m cable runs. He assumed a much greater voltage drop at the camera end. Cable used was copper strand 1mm (or 18AWG). Recommended by both third party electricians. The original 8 cameras use siamese with what looks like 20AWG. 18AWG can carry over 2 amps and the cameras drew around 0.5 amps. Camera details: http://www.jscctv.com/datasheet/new/Dome%20Cameras/JCC-IR963D_IR963HQD.pdf ummmmm, client demanded a cheap white dome :/ Aww feck! IR is rated for 6000 hours of use, thats a year of use. Remind me never to go OEM again. Not been to Florida for a few years........ it´s tempting. Edited July 31, 2007 by Guest Share this post Link to post Share on other sites
photys 0 Posted July 31, 2007 Hey Rory, I hope your Sanyo is ok. Share this post Link to post Share on other sites
rory 0 Posted July 31, 2007 thanks .. a clients actually .. if it was mine I wouldnt mind so much Share this post Link to post Share on other sites
photys 0 Posted July 31, 2007 Well the culprits were Ohms and resistance im told.... Electrician visited and told us that it was a nice job with the right type of wire and terminators etc, except there were too many wires running from the power pack. Seems the volts and amps were acceptable (if slightly high), but too many cameras on these power packs creates resistance and a drop(?) of Ohms. Got 2 fresh power packs with surge protection arriving tomorrow. 5 cameras winging their way from the UK. 2500 mile trip to get to me :/ Too few Ohms messed up my Karma. Share this post Link to post Share on other sites
scorpion 0 Posted August 1, 2007 Will you be adding a fuse block to the power supplys? Share this post Link to post Share on other sites
photys 0 Posted August 1, 2007 He talked about 8 connection points on each of the new power supply units, each with its own fuse. We will see what he turns up with. Hey! What trips a fuse? Volts, amps......too much, too little? Nevermind, time to google the electricity 101 books. Share this post Link to post Share on other sites
scorpion 0 Posted August 1, 2007 (edited) They work depending on the fuse itself. Some are heat activated, and some work with current. Some are actually designed not to blow right away. These are called slow blow fuses. Fuses are designed to melt when a threshhold of current has been reached. This is to give you an indication that there is something wrong with the circuit, and you need to address it right away before you restore power. It can be difficult to trouble shoot when a fuse blows for no reason at all. In florida fuses in devices can blow during lightning strikes. It may not be enough to see the lights flicker, but if there is enough of a flicker a device may blow a fuse because the threshold of current has been reached. Manufactures may spec a slow blow fuse so that the device can take momentary, or close to the threshold current without blowing. This helps in reducing false situations. There are some circuits that are sensitive to a certain threshold, and the fuse is designed to blow very quickly saving the circuit. Sometimes these circuits can be very aggravating, and people will substitute a higher value fuse, and in return they blow a device without meaning to. If you look at a fuse you will see what voltage range it is designed to work with. Some are low voltage such as automobile circuits, and some work at 120 volt range, and there are very large fuses that the Electrical companies use. Circuit breakers in a house will usually work off of heat. When there is an over current situation, there is heat involved, and the circuit breaker will trip saving the circuit. Power supplys for CCTV in the U.S. will come with fuses that blow, or they will come with a self resetting fuse. There are advantages, and disadvantges with each style. If you do not have spare fuses, and one blows then your circuit is down until you can obtain another fuse. It is always recommended to pick up extra fuses in advance. When trouble shooting a blown fuse you can replace it. If the circuit works it does not mean that it is fixed. It can be an intermittent problem, or it can be a time delayed issue. When the circuits heat up it may fail again. Never wrap a fuse with tinfoil. You may cause a fire. If fire marshalls can pin it back on you, then you may be in a very embarrasing spot! If you pop in a fuse, and it blows right away then you have a really bad situation. If you have multiple items running off of one fuse, and you are having problems defining the problem, then remove everything from the circuit, and start adding items one, at a time until the fuse blows again. This will help identify the culprit. You may still have another device that may throw the fuse later when it heats up, so keep this in mind as well. Do not forget that it may be a problem with the power supply, and not the circuits involved. A power supply can have an internal self saving device that reacts with heat. It may shut itself down to protect itself from being destroyed. In the process of trouble shooting circuits this kind of issue will make it coincidental that a particular device is to blame. You remove a camera from the power supply, and you look it over. You turn everything back on, and now the system works fine. Later the cameras go down again. The power supply was cooling off while you were "playing" with the camera (or what ever device). Be very careful with power supplys that come with DVRs. If the inside power supply of a DVR blows it can blow the power supply that is external of the DVR. If you test this power supply on another DVR you may blow the 2nd DVR. You really need to do some good checks before you hook it up to another DVR. http://www.fuseone.com/fuseology.aspx http://electronic-components.globalspec.com/Specifications/Electrical_Electronic_Components/Electrical_Distribution_Protection_Equipment/Fuses Edited August 1, 2007 by Guest Share this post Link to post Share on other sites
photys 0 Posted August 1, 2007 Scorpion: Superstar. Still digesting it all. New power supply is does not have individual fuses. Next one will. It is also 13.8volts. Seems to be the standard kit available here. But the electrician opened it up and twisted a dial so it outputs 12.2. Giving us 12.06 under load at the camera end. Almost perfect! I will be researching proper power supplys for camera systems. I envisage a 16 port wall mounted panel with individual fuses and ability to tune output voltage and amps....... in my dreams lol Share this post Link to post Share on other sites
scorpion 0 Posted August 1, 2007 I am still scratching my head on this one! I guess those cameras are more sensitive then I thought they would be! You said the original cameras are still working! Thats good to know! Can you PM me what kind of cameras those are. I would hate to go on a blind service call and POOF! OOPS! Exit stage left! Share this post Link to post Share on other sites
scorpion 0 Posted August 1, 2007 Fuse blocks for the U.S. http://www.radioshack.com/product/index.jsp?productId=2062258&cp=2032058.2032234.2032302&parentPage=family http://www.radioshack.com/sm-fuse-holders-and-taps--fi-2032302_cp-2032058.2032234.html URLs are for reference only Share this post Link to post Share on other sites
scorpion 0 Posted August 1, 2007 I saw your PM of the cameras. I use a camera that are very similiar to the one you showed me. I have several 16 camera, and 16 channel power supply set ups. I have not had a problem with any of these systems. I am still scratching my head on this one. I do not see too much of a problem with your set up. Except not having a fuse block. Things that make you go HMMMM! What country is this set of yours in? I am going to stick my neck out on this one. I think you have one camera that has a short to the chasis of the camera. Did you pre test the cameras, and did they work prior to the install? Share this post Link to post Share on other sites
photys 0 Posted August 1, 2007 Plastic chasis Pre tested every cam. They worked on site for 2 days. It was a 1 channel power supply. At the moment I belive that to be the problem. Spanish Islands west of Africa. 220V. There are "trip switch" fuses on the mains power board. Hey it was only 5 years ago that Spain introduced an earth on each plug! Previously only 2 pin plugs. I was accoustomed to the UK 3 pin plug with built in fuse. Share this post Link to post Share on other sites
rory 0 Posted August 2, 2007 all this time i thouht you were in the UK Is that Spain? Or are they independent? Are you spanish? Share this post Link to post Share on other sites
photys 0 Posted August 2, 2007 Im a Scotsman, moved here in my twenties. Semi independent Spanish islands. In many ways, a tiny version of your island Rory. Share this post Link to post Share on other sites
