One day – one job

ONE OF THE THINGS I FIND REGULARLY with new installers wanting to join an inspectorate is the vast difference in time taken over an install. I hear of lads that take two days-plus on the one hand and, on the other, lads that can "bang one in" in three to four hours.

The question always arises: Why the vast difference? As an inspector I always got to see the finished product but very rarely the man at work, so some of the tricks and shortcuts may well have eluded me. On the other hand having done over a thousand systems myself I have managed to learn a few "wrinkles". For a start let's put one thing straight, unless your off duty name is Clark Kent "banging one in" in four hours or less means only one thing – you are cutting corners and I can almost guarantee that your systems will not comply with any known standard between here and eternity. At the other extreme, the lads that are claiming two man days or more to fit a normal domestic system in a three bedroom semi need to revise their way of looking at things too.

How do I measure this and arrive at my times and answers? It's just my own experience.

In the early days it used to take two of us two days to do the fit and I would have to go back on the third day to do the snagging and hand the system over. Over time we learned faster ways to do things, with aids like battery screwdrivers, hammer drills and staple guns, and I dispensed with my partner and got the job down to one man – one day. Here are some things I learned:

Investigate the layout
The first tool you take in is the vacuum cleaner: at this point you have won the heart and mind of the lady of the house and she will often be confident enough to not follow you around all day.

Investigate the layout of the place and plan where you are going to run the wires and tap into the mains. A half hour of thought and investigation could save two or three hours of work. Try to get rid of kids and animals. "Sorry to pester you love, but can you keep your son out of my tool box – there are things in there that will cut his fingers off" usually takes care of the kid. With dogs, I usually find that if I drop something noisy on the floor (an empty tool box) when the owner isn't looking then yell and curse and be caught rolling about on the floor holding my leg usually has the owner putting the dog in the garden. Large dogs can be a problem when you're on your hands and knees and they approach from behind with amorous intent. A quick blast with WD40 puts him off but don't let the owner catch you.

Drill all your holes first. Getting tools out, putting them away and getting them out again is a huge time waster so do it all at one go and do it right first time for a fast finish. Next, put the control up (loosely enough to get the cables in) and get it charging the battery, it makes the readings more accurate come commissioning time. Put the dummy box up and then the real bell box. It always helps to get these up before the daylight goes on a winter's day or before the rain comes (on any other day), and it means you are not lugging that ladder up and down too often.

Put your detectors up (leaving the covers off) and run the cables back to the panel marking them as you go (always leave a loop of spare cable near the detector so it can be taken down and replaced in later life). At the panel cut your cables to length and strip back the outers. DO make sure that you don't cut your cable marks off, you won't be the first to end up holding a fist full of off-cut cables all neatly marked. Twist your individual wires into pairs – it's amazing how much time is wasted searching through a bird's nest of wires for the pair you want next.

Now is probably the bit that saves more time than ever – do the readings as you go. Putting the wires in and testing the system then taking them all out to do the readings is the biggest waste of time going. Once again doing things in the right order will save time and effort, join all the 12v positive wires and connect them.

You can now take a current reading on each detector using the negative wires and comparing the reading with the detector's spec sheet (from the manufacturer). It only takes a few minutes and most of that will be waiting for the detector to settle. Log your readings, any defective units will probably show themselves at this stage by disagreeing with the current specified by the manufacturer. (It also helps to confirm the validity of the 12v power pair because we don't take resistance readings on the power lines).

Why we left the lids off
Connect all your negative wires, now you can go round and take the voltage readings at the detectors and put the lids on, remember, we left them off, now you know why, it is a waste of time to put them on only to take them off again to do the readings. Now you can take all the resistance readings before connecting up, all you have left now is the programming and the bell voltage and current from the power supply readings.

Let's have a look at some of the logic involved. If you put the panel up very early on it can be charging the battery so that it is not flat when you come to take the readings. A flat battery fresh on charge will pull the voltage of the system down and you may get a false volts reading at the detector heads. Getting the readings wrong is worse than not doing them at all because it is misleading and therefore totally pointless.

Doing the dummy box(es) first may mean that you can leave your ladder near the main box so you don't have to hump it back and forth to do the final connections and readings at the bell head.I proved to myself beyond doubt that doing things in the right order saved my company a lot of time and money – and I met the standard in the shortest time. The only snag with this running order comes when we get to end of line resistors.

The object of taking resistance readings (Fig 1) is to verify there is no damage done to the cable during the fitting. With the end of line resistors in place it is virtually impossible to get a useable reading and the advice up to now has been twist the ends of the cables and take the readings – then go back and fit the resistors, a very time consuming method. So why not try this one:

Wire up the system as previous until it comes to the voltage readings at the detectors. At this point twist all the detector wires together in the panel and as you go round taking the voltage at the head reading and putting the lids back on, take the resistance reading from either side of the end of line resistor. As you will see from the drawing (on previous page) it will read the cable and all your joins but ignore the E.O.L. resistor enough to get an accurate circuit reading. I found that I could eventually install a system to standard in a good working day without sweating like a bull. Hearing stories of much lower times just makes me think they are cutting corners on a big scale.

Speaking of standards, we now have a revised and updated BS7858 for security screening and we are expecting the new revision of EN 50131-1 sometime soon, and of course there are a whole raft of other standards currently under review and re-issue. We in the trade are expected to buy and keep buying the new revisions that appertain to our respective trades but, and it is a very big but, how do we know we are buying the right issue number or revision? For those within the inspectorates it shouldn't be a problem.

Stung by a standard
I recently visited a couple of companies who have bought the 1996 version of BS 7858 only to find that a new revision appeared within the month, so they are facing having to buy the standard again – and that is quite unfair. OK, so the BSI had to fix a date for the introduction and the 1996 version was valid one day and the 2004 version was valid the next, but if the information had been available to the companies in question would they have bought or would they have waited? I tackled the BSI about it. The information is there – if you are in the right place and you know where to look.

If you order a standard by phone from BSI then the operator taking your order should tell you if there are any updates or revisions due – provided they remember. If you appear to know what you want and just order the number would they offer that info or would they assume that you knew and just send the soon-to-be out of date copy?

If you order on line then the info is there provided you know where to look. On the web site if your standard says just "current" against it – it is the one to buy. If it says "Current – work in hand" it means that a review is currently under way but it doesn't tell you when the new version is due, and that may be tomorrow. For dates due you have to look in the section marked "project line". The problem here is that now I have told you it seems blatantly obvious to look there ... but did you know that before or would you have guessed? Probably not. Next – if you order by fax there is no way that BSI can tell you and you will get what you ask for, and if it is out of date next week then that is your tough luck.

We are currently facing a situation where EN 50131-1 has been brought in to supersede 4737. 50131-1 is also currently under review but its scheduled release date is as yet unclear. Do we buy or do we wait? For companies within the inspectorates, the information is already going out. The problem for those on the outside; if they don't know where to look the info is not readily available to them. So get advice before you buy.