ljarrald 0 Posted February 28, 2012 i was speaking to the caretaker of my school yesterday and she asked me to fix the cctv system which i'll be looking at today. we ended up talking about it, the site is massive but they only have three cameras. there is an adventure playground there because the building is also used as a community centre. they have one static camera covering a part of it and she said how they wanted more coverage but didn't want amillion cameras. i suggested keeping the static camera as an overview camera, and installing a PTZ next to it that can be put on tours/manually controlled etc. she liked the idea so hoping that they'll get me to do it, i need to know a couple of things. i have installed PTZs before using cat5 for power/video/telemetry but they used the video signal for telementry. their DVR can't do 'up the coax' control so i will need to get power, video and control to the camera. can i put all this in one CAT5 cable, or will i get interference? the cameras are all mounted on lighting poles so i could take the power locally from them and then i'd only have to worry about control and video going back to the building... thanks Share this post Link to post Share on other sites
Soundy 1 Posted February 28, 2012 How many times has this been asked now? You WILL NOT get interference by running power, video and data in the same Cat5. Both the balanced line created by the baluns, and the twisted-pair design, work to reduce induced interference, and Cat5+'s design of different twists in each pair is there specifically to reduce cross-talk between pairs. The only real concern is that PTZs tend to draw significant current and two pairs of Cat5 may not be sufficient to supply it over longer runs... however, if you can power the cameras locally from available AC, then that's not a problem either. Share this post Link to post Share on other sites
the toss 0 Posted February 28, 2012 You may find that there is only power at the lighting pole when the lights are turned on. Share this post Link to post Share on other sites
tomcctv 190 Posted February 28, 2012 the cameras are all mounted on lighting poles so i could take the power locally from them and then i'd only have to worry about control and video going back to the building... i can count on 1 hand the number of cctv companies in the manchester area who are licenced to mount on power polls. so if i was you i would mount the PTZ camera on the building and do everything with existing power points. and that way you can also use the existing camera as a alarm point for te PTZ ... giving the ptz more options which is better than just a tour. Share this post Link to post Share on other sites
ljarrald 0 Posted February 28, 2012 the lighting poles are on the land owned by the center and are owned by the center, they're not council ones or anything. or do you need a license to install on any pole? all but one of the cameras are dummies anyway. Share this post Link to post Share on other sites
tomcctv 190 Posted February 28, 2012 the lighting poles are on the land owned by the center and are owned by the center, they're not council ones or anything. or do you need a license to install on any pole? all but one of the cameras are dummies anyway. if its a school then its council owned / if its public space (which a school is) all electrical work has to be done by a licenced company. (just power side) nothing wrong in having a company install a power point for you ... its just the the certification needs to be held by someone Share this post Link to post Share on other sites
fa chris 0 Posted February 28, 2012 In the US street lights are normally over 400 volts, good chance you'll run into something similar over there. You'll need it stepped down to 220vac in order for you to plug in a cctv power supply. Have the school get the electrical work done by an electrical contractor for you, just specify what you need. No need to roll the high voltage work up under you. The light poles also need to be set up properly in order to mount cameras on them, they need a sleeve or some type barrier in them to separate your cat5 from the high volt lighting power. The poles with real cameras on them should be set up fine, the ones with dummy cams may not be. How are the current cameras powered? Are they run on coax? Mounting on a building is a lot easier than messing with poles. Share this post Link to post Share on other sites
ljarrald 0 Posted February 28, 2012 here in the UK most streetlamps are single phase 240V. the ones at school have several floodlights on top so it is very possible the supply is from two phases at 415V. when doing electrical work, can i do all the first fix like running cables and connecting them to the PSUs and stuff and then all the spark needs to do is connect it to the mains? or does he have to do it all? i know working with poles is a pain, but running cables through the building would also be a pain. and the housings are already mounted and i can get cameras a lot higher on the poles as the school is only a single story. i will probably end up using wireless to get the video back to 'base' to save time and money. there is a switched spur in the reception (that anyone can press, every bloody fuse unit in the school is on a switch, they really shouldn't be) that says CCTV on it, when its switched off the camera loses power so its powered separately to the lighting pole. video transmission is through coax. Share this post Link to post Share on other sites
rory 0 Posted February 28, 2012 If you are not a trained electrician you should not even be considering it. Sub it out. Share this post Link to post Share on other sites
jeromephone 6 Posted March 1, 2012 Agreed if you are not licensed for high voltage why take the risk especially at a school. In the US anyway there is a device called a power tap which locks into the photo cell socket and then the photo cell locks into that apparently the photo cell is getting 110 all the time. http://www.solisenergy.com/documents/LPT100_DS.PDF several companies make something similiar Share this post Link to post Share on other sites
