Melcom St6100 - Rewire Or Replace Tomorrow?

[james.wilson]

the optima doesnt have the comms outputs of the accenta though bear in mind

[fozzies]

Could take a relay off the bell trig o/p, ive seen that done (for the sd1)

[sjsturner]

Could take a relay off the bell trig o/p, ive seen that done (for the sd1)

Seen this many times

Your electrician friend was wrong, solder them.

Qfa 3

I always solder connections and heat shrink, pretty much rules out a bad termination.

[arfur mo]

twist connections made about 15 mm long then bent in half will give a secure connection but better to use protected terminal block.

covering with insulation tape is a complete no no in my book, i hate that practice with a vengeance. the glue gives up leaving a sticky residue, this goo then gets into the connection, and causes high resistances - thats if it don't fall off causing shorts. You go back to it later and get this goo all over your fingers uuuuuk!.

if no terminal block, use a thin sleeving, even your sparky mates green/yellow 5amp systoflex. anything but tape. personally, unless external or damp problems i would not advocate use heat shrink, as it can hide what is a bad connection due to compression aiding contact, you have to remove it to check properly, making future fault finding more time consuming when breaking down circuits.

all that said, if you have bad connections (as it indicates to me) replacing the controls is an expensive fit and hope to cure option and not guaranteed to fix it, its more of a clumsy 'grape shot' approach, no diagnostics undertaken.

it could be likened to replacing your aged car engine due to crunching gears, you fit a new clutch because thats sensible and that was the real fault, the new engine was not the real cure but will seem it from the 'evidence' of success.

if you do replace and all is well, likely you have remade the bad connections in the process, it is not proof positive that your original panel was faulty.

A competent experienced alarm service engineer would soon assess, test and zero in, having trusted test methods to track down the real causes of the faults.

by all means get a new panel for later design innovations, but you could remove all zones and tampers, fit links (or resistors) in place then see if the panel mis behaves over a period, and what i would recommend short if engaging an alarm co.

[arfur mo]

Seen this many times

Qfa 3

I always solder connections and heat shrink, pretty much rules out a bad termination.

with all respects, can i challenge that?

first off, this job is in single core cat5e cable, nothing wrong with that, even EN standards say 'suitable for the purpose' not standard as under old BS.4737 (coo! get me ). Admitted not my favourite cable for alarms but if telecoms can handle it, so can alarm systems and i see no reason to replace out of hand based in preferences.

when you solder, a lot if heat and also flux is used to ad the proper solder connection, flux is corrosive to copper. while the tinning will protect most the copper, invariably the action of removing the sleeve with side cutters causes a slight knick on the single core, exposing the copper to the flux and eventually causing faults.

if you want to test this out, stripe some spare solid core cat5e or comms cable, remove the casing on some cores with side cutters, now wiggle the cores with your finger tip on the end, most times it will weaken and snap at the point where you nipped it to remove the sleeving.

[fozzies]

Ive been solder joining for 22 years now, and not one has failed

[sjsturner]

I dont use flux arf not on stuff like that.

But i have never had to re- terminate one yet.

I cant say the same for blocks crimps and twists.

Cat 5 is delicate though

[Simon K]

the optima doesnt have the comms outputs of the accenta though bear in mind

 

Oh wow, thank you for catching that.  Confirmed from the engineers manual: "These outputs are not applicable to the Optima compact panel".  You just saved me from making a horrid mistake, really appreciate it ).

 

So now choosing between the "Mini":

 

http://www.securitywarehouse.co.uk/catalog/index.php?main_page=product_info&products_id=864

 

and the "Poly":

 

http://www.securitywarehouse.co.uk/catalog/index.php?main_page=product_info&products_id=1468

 

Are the "Mini" and the "Poly" identical except for size?  Does the "Poly" simply have more space inside (making it possibly easier to work with)?

 

-simon

[cybergibbons]

Flux in electronic no-clean solder doesn't cause corrosion. NASA are fine with it, so am I.

[arfur mo]

Ive been solder joining for 22 years now, and not one has failed

i'm all for sound connection methods, in normal circumstances soldering and heat shrink is not required over competently made terminal/junction block, inmho over engineering for no advantage so need. i ask this, why solder intermediate connections then use the terminals in the devices, and not solder to the lands on the back if the pcb?

the answer us the same as follows, it's when it does fail or a suspected fault occurs on a length of cable, a service engineer will not thank you as it really makes it a pai to part the joint when your if looking or short or especially an earth leakage. re-heating the wire will likely cause enough damage, so you have strip back.

over the years those cables get shorter from service engineer investigations, and this is after removing the heat shrink (if used).

please accept i do appreciate your professionalism and care, and i'm not dictating, just showing you my personal way, and the thinking behind it (based on my 45 years experience going in to fix faults).

i a do a notddin widout finking innit! .

I dont use flux arf not on stuff like that.

But i have never had to re- terminate one yet.

I cant say the same for blocks crimps and twists.

Cat 5 is delicate though

if you use multi-Core solder the flux is already in the solder, you can't solder or braze for that matter without using flux