I like isolators. They are good because they turn things on and off. The red and yellow ones are my favorite because it's the same colour as my little tikes car.
I've been fitting Scame isolators for quite some time. They are certainly the top of the range. Easy to work with and look smart. I always keep a few in stock. Also the pvc material used for these isolators is very good as compared to others on the market. They cost a little more and definitely worth the price. Scame are the Ferrari of the isolators. I'm a Heat-pump engineer for more than thirty years.
There was a data center in London that had a significant problem with homeless people. They would sleep rough next to the air pump equipment, because they blow out warm air, so a nice source of free heat on a cold night. The problem was, that at some point a homeless person would turn off the isolator because it was noisy and keeping them awake. The establishment wanted to remove the isolator, but it was the fire service who said no. They wanted isolators. We argued that if the unit was on fire, you couldn't reach the isolator anyway. Right ole kerfuffle.
The Scame isolators are great, nice and roomey well thought out. It's a shame most wholesalers stock the generic chinese tat with no room for glands and wiring, with earth clamps that fail to clamp unless you crimp on a 'lug' . The trouble is installers buy the stuff, moan to themselves but don't complain to the sellers.
According to the SCAME catalogue the pole descriptions that are labelled SN are a SOLID (i.e. unswitched) neutral. Consequently 3P+N is a 4-pole switch and 3P+SN a 3-pole switch with an unswitched neutral.
Agree that they do not need emergency isolation as it is not normally something people are going to be tinkering with in use like a machine with a manual injury risk .Saying that I do think there is a risk of small children poking sticks and things into the fan and would therefore think locking it into the on position may possibly not be wise .
Isolators are really for maintenance work to be carried out safely. Switch off at the MCB, then isolate by switching the rotary isolator to the off position and lock off. They are not really for emergency switching and often not designed for breaking large loads. If these isolators are considered emergency devices they should be brightly coloured and red/yellow seems to be Industry standard. If these are intended for their proper use, maintenance, the black and grey Scame versions with the centre drill points look excellent Great demo lads
AS3000 in Australia states all air-conditioning equipment must have a isolator mounted near the unit I believe it's for refrigeration techs who have only restricted electrical lic to be able to perform maintenance and repairs as the system isn't directly connected to the consumer unit breaker
Wow, I have struggled with the 'off the shelf' isolators from my local wholesalers, no room at all in them to work, even with cable as small as 2.5mm. After this video I am going to order some of these for stock. Thankyou for another great video. Alex.
I’m also wondering about the location of those isolators. If they really are intended for emergency use, having to reach over the unit to operate them seems less than ideal.
As someone whose in the trade, they do need local isolation for pumping down if you’re working on them. Depending on the set up of them. Unless people are willing to pay for 2 engineers to attend properties. So the sake of an isolator switch it’s a bit daft no? Also they should start making them more like a coldroom/freezer room like the danfoss optyma where they have a built in switch. would look far better and neater.
Hypothetically, if the system omitted the isolator and you had to isolate them by turning off the circuit at the consumer unit, why would that require a second engineer rather than just walking back and forth a time or two?
@@JasperJanssen You’d then be running the compressor on a vac, potentially damaging it and/or it would cut off and thus the gas would then fill the lines as you can’t close the valves in if you’re going to stand at the consumer unit, meaning the pump down was completely pointless. The only other way to do it would be to reclaim the gas the, then you’re looking at paying for an extra hour or two for someone standing watching a reclaim unit. So swings and roundabouts. There’s also different situations where you need to turn the switch off when checking valves, or disconnecting the reversing value. Get local isolation and it elevates all these issues.
With air source heat pumps I agree the red yellow isolators are crap. However the bigger problem Is the air source pumps. Before any one gets a grant and pays big money rhdy should be aware that when they need heat in winter the efficiency of an air source heat pump falls dramatically. Check out Mitsubishi technology why maintains efficiency to very low winter temperatures.
I do agree that they probably don’t need an emergency isolator outside. Quite what they think will happen I’m not sure but.. the worst thing about them is how they fade after a matter of weeks/months and become even more unsightly! Excellent channel btw 👍
Here's something wild and crazy, why don't manufacturers build them into the unit, like you see on electrical panels, they are not exactly tight for space, plus why not incorporate a key switch as well to stop them being turned off, as usual there's no thought in the design. And it's up to someone else to over come the problems, usual the electrician.
Good point on possibly not needing a form of emergency isolation but i do know from my own experience of changing out equipment that a form of local disconnect is a lot handier than needing access to the property.
As units change to R290 -Propane, as the refrigerant gas, a means to quickly and safely isolate with no risk of sparks in the immediate area would be well advised. Safest area is to the side, min 400mm up, (propane is a heavy gas) and cir 900mm to the side. Locking on is useful in communal accessible area’s but not advised.
I fit those fire 🔥 rated isolators to sprinkler pumps.. Smaller ones to industrial fire alarms systems... You'd never see them in a domestic dwelling, usually commercial and industrial settings...
An isolator for emergency switching doesn't need to be red and yellow. A red and yellow switch denotes an emergency stop which, when reenergised, shouldn't restart the machine without another positive action.
as a hvac engineer myself i would say locking on isolators for most heat pumps is a bad idea just purely because of the likelihood of the customers loosing keys etc. but they definitley need a means of local isolation
On the plus side, cutting off the lock from something locked on is inherently a safe action. On the minus side, walking around with bolt cutters in loto cabinets might still be frowned upon.
They need isolation, but that can be achieved through various means. Also they often need some form of overcurrent protection. For single phase 13A units surely a FCU installed in a suitable inside location makes most sense? Can be isolated and fuse holder can be locked open with padlock for maintenance. For three phase you could even lock off a 3 pole MCB - again this isn't isolation for mechanical maintenance, and according to regs an MCB is suitable for isolation and functional switching. Most MCB manufacturers provide a locking off kit.
On a communal block of flats where I have worked the communal lighting have light fittings with 2 lamps with one permanent 24 hour supplyvand another switched from an external photocell also an emergency circuit in every 3rd light, they have 2 red/yellow rotary isolation switches for testing the emergency and over riding the photocell to check lamps are working. Both are padlocked in the on position which had to be drilled to get the padlock in, could of done with those grey black switches a couple of years ago.
Great point about the isolator switch's here! Question why is it needed at all? could you not just trip at a consumer unit? Note not a sparky as per my efixx challenge wall
Theres possibly some british or EN standard that requires red and yellow for ease of locating and indicating function and close by to enable shut off for remedial work or fault situation similar to regs regards e stops
Presumably the difference between 3P+N and 4P is timing of the 4th pole? In a 3P+N, the neutral is connected first and disconnected last but in a 4P they're all connected / disconnected at the same time? Final assumption is that the 4P is aimed at single phase supplies that need additional isolation for some reason, such as mains voltage control circuits?
Agreed, usually the make and break sequence of the poles would be simultaneous with the 4 pole version and first on/last off for neutral with the 3 pole+neutral version. Doesn't always work this way though, I'd suggest checking the manufacturer spec sheet to be sure.
They are not an Emergency isolator as they do not prevent reclosure of the device. They are in fact a lockable isolator to enable the circuit to be locked off by the maintenance engineer. Therfore In this case they are used as a Safety Isolator. In this case they should not be locked in a on position for the following reasons:- a.) The maintenence Engineer may not be able to access the circuit isolation for the plant. b.) The Duty key holder may not be available to remove the lock from the on position. C.) Loss of keys . From your consumer unit installation situated at the bottom of a staircase which was installed at a low level you didn't seem to be concerned as for children gaining access and switching the circuits off.
Do these isolators have the ability to switch off on load guys? There will be a sign on it if it's rated as such If not it shouldn't really be being used as a functional switch or an emergency really. Maintenance only
They do look better. But still looks like very little room? I’m using the BG ones at the moment they are big but curved, offering a different aesthetic to a square isolator, but my god they have bags of room inside! So refreshing and they save time- Why don’t you do a comparison…speed install test on them….?
1, does the isolator need to be located by the equipment? If not then it can be out of view. 2, if a property is dependent on electricity and there's an outage such as the recent one in the North, they're screwed!
8:23 - I love the slim, flat, front, but the "back box" is a bit blocky... Can the rear of the box be mounted into the wall, similar to a conventional socket back box? Purely for aesthetic reasons...
I ABSOLUTLY HATE captive screws - I've had too many fall out at inappropriate times - so I much prefer to rip the screws out and put them somewhere safe - so safe, I can't find them later !
Great video guy’s but your missing one very important point, the is the isolators are red and yellow for a reason, the is so in the event of an emergency we and the fire fighters know what to turn off. Can you imagine the fireman’s switch being anything but Red . Also I don’t like the idea of locking it in the on position, what happens if there is a fault and you or someone has lost the key to the paddock? The isolator could over heat and cause a fire? , but I have to agree the black and grey one does look better. Fantastic video guy’s as always 👍👍❤️
If the manufacturers say an 'emergency' isolator should be fitted, then that is what you fit. Whether you like the look of them or not is totally irrelevant. Even the regs state that manufacturers instructions over ride the regs.
@@FutureCurrent If the manufacturers say an 'emergency' isolator should be fitted, or even taken into consideration, this is the same thing, manufacturers instructions override the "guidance" in 7671. be clearer on the information you spread
@@brianhewitt8618 absolute nonsense, some of the crap I've seen in manufacturers instruction has taught me to take them with a pinch of salt and make a professional decision.
@@FutureCurrent I agree that some instructions are utter tosh but you still have to follow them, if you don't it won't be a good defense if anything were to go wrong, that's why you pass the buck and not hold on to it
Any advice on preinstalling flow and return under my kitchen extension being built before ground work completes? We want to lay the 28mm flow and return under the concrete floor to hide it all instead of retro fitting the pipework at a later date.
I'd say the future is producing electricity economically before saying heat pumps are the future. Before heat pumps id even put insulation of properties first.
When some clothing has been drawn in to the unit, you need to be able to turn it off sharpish. The location of the isolator should be such that it's out of reach of young children, but I wouldn't want to see it locked on in a domestic environment.
I think the red needs to go. In the US we have gray metal boxes with a lid about the same size you flip it open and you pull out handle kind of handle disconnect with teeth that break the connection. We called them disconnects. They are required on anything that might need to be serviced that's not directly next to the electrical panel. I say this because one day I was at a library at night doing an outdoor movie. We had a big gust of wind come through and something fell down and made a big noise between a house and a building next to the parking lot we were in. I wandered into the alley to find out what the loud grinding noise was that I was hearing. it was due to a bunch of doors that we're leaning against the wall and caught the wind and blew over and hit the air conditioner knocking the fan out of alignment and it was scraping against the casing. Thankfully no idiots locked the disconnect so I was able to pull it out and they had the Business number on the building so I was able to call them and leave a message so when they got in the next day figure out why there was no air-conditioning. It's probably save them a lot of money and repair costs as well as somebody needed to do was properly fix the fan rather than replace the fan. I like those new isolators and wish we could get some of those over here. On that note I think people lock them to prevent theft, in reality they only really need to be locked when you need to lock out for service. As in another instance I showed up at church early to set up on Sunday morning and the sanctuary was a bit warm turns out somebody stole the air conditioner and they didn't even bother to turn the power off they just cut the cables and pipes and took the whole unit outside.
As always a good video! Maybe consider to put some acoustic dampers on the walls and ceiling of your studio to cut down on the reverb and also level the mics of your hosts to one level, the right one is pretty loud, it makes hearing sometimes pretty hard ;) But otherwise go on, I really like your videos!!
Very interesting video and commentary as usual, as with any item good design and possibly end user input an excellent all round product can be produced. Keep up the good work and stay safe.
It should be time to bin the ugly Air Source Heat Pumps entirely. How anyone would want that monstrosity on their property and taking up space in their garden puzzles me.
It would be great if someone could develop a whole-house heating unit that could be mounted indoors, making little noise, and taking up no more volume than, say, a kitchen top cupboard.
People were saying that about satellite dishes over 30 years ago. I agree they are not pretty but they will become common place like air con units in hot countries.
@@paullyons4624 there was an article in one paper where a family had one of the heat pumps installed and got a grant. They found it didn’t give enough heat or work properly so the ripped it all out and put a normal boiler in. The photos showed the boiler in the kitchen and the heat pump in a skip. How would you fit one of these to a flat flour floors up, even if the freeholder would give alteration consent, which many wouldn’t.
Get out of town they look lovely I fit them all the time. Once again stupid manufacturer assuming we all use wood screws to mount the isolator, 90% of the time an isolator is fixed to steel and the fixing points need to be large enough to accommodate a 6mm roofing set screw. This is why the back gets drilled and it ends up full of water. Big red isolator would be for the emergency fire pump motor or emergency engine start up system or switch room fire suppression system. Craig and Derricott Ltd do a lot of that and they are located in Walsall