sharpener

Yes swap the wires going to terminals marked V and W. Good luck!

See https://en.wikipedia.org/wiki/Three-phase_electric_power#Three-wire_and_four-wire_circuits for an explanation. In Italy and much of continental Europe they have 3 wires plus earth. Houses often have a 3 phase supply, which is 230V from one phase to another. There is no neutral, all three wires are live. Everyone else calls this delta after the shape of the Greek letter but the Italians seem to call this triangle. In the UK we have four wire plus earth three phase connections. Single phase to the typical house is 240V between one phase and the neutral. We call this star, the US calls it Y or wye. The phase to phase voltage is 415V (which will burn out your motor). Do not worry about any of this, I am convinced the motor is right for the VFD but may be running backwards. Do the test! Edit: Well Tom P as their UK agent knows this is what you are doing but it doesn't sound as though he has been able to come up with a solution.

And what if you want to add say a DIN rail meter to an existing board? AFAIK Eastron don't sell breakers or enclosures and Crabtree et al do not sell meters. Not readily available at trade counters anyway. BEAMA are not a regulatory body, they are the trade association with the specific task of protecting their own members' interests (I had a lot of dealings with them when I was at the DTI). So no-one is going to state that another's components are compatible even if that is manifestly the case. Crabtree probably wouldn't even tell you you can use their Loadstar accessories in a Starbreaker enclosure (but not the other way round). It's typical protectionist behaviour, though nowhere near as bad as battery drill manufacturers all having different incompatible batteries. /rant

Can't see any colour code for the connections mentioned in the VFD instructions, sounds as though it may be arbitrary. Is there a direction arrow on the body of the motor or pump? (I appreciate it is a packaged unit so may not be possible to see which way it is rotating.) Try swapping e.g. the brown and black at the terminal strip and see if it is any better. It is not likely to cause any harm for a short test run. I see you can also do this in the VFD software settings but personally I would swap the wires to be more confident that the test has actually been performed.

I think that is the power consumption of the pump on its own, not the pump/VFD combo. To first order, the flow rate will go down as the delivery head increases, as @SteamyTea implies the power into the water is the product of the two so might well remain relatively constant. Hydraulic output is delivery head in m * 9.81 * flow rate in l/s. Maximum output power will be at about half max flow rate, e.g. for the DAB 102 pictured above 3.5 * 9.81 * 0.6 so about 200W, these small jet pumps are not very efficient (you would not use them on an industrial scale or at Dinowig) and most of the rest is motor and impeller parasitic (drag) losses which are constant and independent of flow rate. Doubtful, you do not say the colours but I would certainly expect the earth to be green/yellow. Phase wires might be all brown (possibly numbered 1,2,3) or brown, grey, black, or something else. Have you disconnected the motor from the VFD and reconnected it? It is possible you have got two wires swapped and the motor is running backwards, it might still pump after a fashion even so. IIRC there is something about this in the VFD instructions, failing which swap any two of the phase wires with each other leaving the third as it is, see if it goes any better. Did they just test the pump or the pump/VFD combo? If you have exhausted all the above it is infuriating but in the interests of having a reliable water supply in a remote off-grid location may be better to cut your losses and install a small single phase pump either from the same or a different mfr depending on how you feel about them. Tom P might even be willing to give you a discount for persistence!

Yes, subject to them providing the functionality I need (and have discussed with his boss), which is to run the HP from the battery system not the incoming supply. So my favoured approach to the current issue is to put a 32A Type C mcb in the existing board, and then take a 4 sq mm cable to a sub-board with their Type B RCD, the meter and a 6A mcb for the control circuitry inside it. Avoids the need for any heavy gauge meter tails too. Will phone them tomorrow with this proposition. Yes, hence I have standardised on Starbreaker fittings, there are 3 sub-boards doing various things and it has allowed me to swap accessories as the system has evolved. I already have their 4 module mini CUs housing an MK two-module SPD, a two-module Eastron meter and a different single module meter, the busbar doesn't get in the way. Just checked, it will also take the entire innards from a Proteus garage unit dating from 1995, so I have high hopes it would accomodate this Proteus Type B RCD though £200 is a hell of a price. Personally I don't see the problem in assessing mechanical and electrical fit for myself, but the mfrs of course say they won't warrant this use, largely out of self-interest. Electricians are after all happy to use unbranded generic DIN enclosures, what is the difference?

Much confusion has been caused by the authorities allowing the use of the word "type" for two entirely different concepts For mcbs (miniature circuit breakers) and rcbos (residual current breakers with overload protection) the Type is the overload tripping characteristic, with the most widely stocked being Type B: immediate tripping on 3 to 5 times rated current (most domestic situations) and Type 😄 5 to 10 times (small motors and HPs). OTOH for rcds (residual current devices) the Type is the level of protection against DC fault currents with AC being the least and then A, F and B as per the diagram here. As noted above type F appear to be adequate for single phase VFDs, but don't seem to be specified by HP mfrs, even for models which do not come in a three-phase version.

On a early site visit the head of the firm agreed they would fit extra mcbs to my CU and this was echoed on drawings I sent them 6 weeks ago. He didn't mention anything about a Type B RCD then or at any other time. Better I suppose it comes to light now than when their electrician turns up the week after next with the wrong bits. It is not straight forward because (as previously explained to them) the HP has to be fed from the 50A battery inverter output. It can't just be teed off the meter tails with Henley blocks which seems the usual approach. I have also got a DIN rail mounted meter which needs to go in the circuit somewhere. I went through all this with the previous people (who failed to install before Easter as they had promised) and they didn't mention anything about a Type B RCD either. Perhaps some regulatory body has recently issued new guidance/reminder. The new meter goes on the rails and fits correctly through the aperture on the Crabtree Starbreaker CU, which was there in 2007 when we bought the house, maybe I have been lucky. Unfortunately they don't do a Type B which is odd because of their increasing use on EV charging point circuits. Agreed. If to Euro standards it should work off anything 230V +/- 10%. UK supplies are for historical reasons 230 +10% -6% so at the upper end. And I see 250V at some point most days so very close to the highest permissible voltage. Fortunately it is a stiff supply so my PV doesn't push it up noticeably.

Thanks, found it. It's a bit tautologous as it says "if these are stipulated for the installation site". Who does the stipulating? IMO this was drafted for the German market where the 3-phase model is more or less universal. In the UK on single phase I think a Type F would be adequate as per the link above. They are only 2/3 the price, though still over £100 e.g. this one (which is a standard 2 module DIN rail fixing so looks as though it could go in my existing CU, subject to my comparing the detailed dimensions).

Ours is a Model 1 commissioned on 26/6/95, although many parts have been replaced over the years so are not that old. We are in the S Hams so within a reasonable distance from you. If you can let me know what parts you are interested in we can probably work out if they are compatible.

Have just been informed I need to have an additional CU with a Type B RCD for my upcoming Vaillant HP (Arotherm + 12kW). Previously I had been led to believe they would just fit 2 extra mcbs in my existing CU for which there are sufficient spare ways, but they now want to fit a subsidiary board instead. Has anyone else encountered this requirement? How important is it? Is Type B even the correct spec for a single-phase inverter-driven HP, this site suggests that a Type F is adequate and Type B is only requried for 3-phase drives.

Hi again @Hastings. The X-JE120BT does have a three-phase motor according to the FAQs here and this catalogue page, I think the T is the Italian for Trifasi. The fact that the space on the rating plate for capacitor size is blank is consistent with that bc it will not have a capacitor (but not conclusive, the Amps space is blank too). I am not sure what the Vc is, perhaps the voltage rating of the capacitor when one is fitted (single phase models only). What colour wires does it have? I would expect a 3-phase motor to have 4 cores, viz 3 phases and one earth. If you have a multimeter and it is not damaged you should get the same resistance reading between any two of its phase wires (three identical readings in all). I think the "230" on the rating plate confirms it is the T230 model which has the correct windings for a continental delta-connected 3-phase supply suitable for the VFD (see my queston upthread). So do not connect it to a UK star-connected 415V 3-phase supply or you will burn it out. I assume from yr use of the term static pressure you have tested it against a closed tap/no flow condition (although @JohnMo seems to think not). In which case (i) the pressure seems much lower than it should be (ii) I am surprised the pressure vessel makes much difference. If the combo does not perform properly on a decent mains supply then I think this at least partly exonerates your battery inverter system and calls into question the bench tests that your supplier has carried out. Did you get it from a distributor? Maybe it is time to contact Steelpumps direct. I had a brief email exchange with their technical director about filters and he was quick to respond (though it was not ultimately the right answer): Tom Parry Technical Director for and on behalf of 3P Technik UK Ltd - Water Management STORMWATER TREATMENT | RAINWATER HARVESTING | PUMPS & CONTROLLERS | GARDEN TANKS E: tomparry@3ptechnik.co.uk T: +44 (0)1239 623506 www.3ptechnik.co.uk ¦ www.steelpumps.co.uk ¦ www.mac3uk.com

Total cobblers as @JohnMo has said. What is he proposing to connect the second coil to, the Eddi or directly to the PV panels<g>? If a well-insulated house you will only need a (proportionately) small HP so why not do it right away? If not then I agree, small system boiler plus heat-pump ready unvented cylinder. Not too big, guidance is 45 litres x (number of bedrooms +1). Explanation of different heating control wiring options at https://flameport.com/electric/central_heating/heating_wiring_S_plan.cs4.

Anyone want spares for a Kidd boiler like this? Ours is going to be replaced shortly with a heat pump. It has a standard EDGB Inter 2011 burner so if anyone would like any parts for spares, the motor, control box, oil pump, photocell etc are all in good working order having been serviced regularly. Probably usable on many other boilers with the same or similar burner. Have already put on local FB and Freecycle but so far no takers. It seems a pity to scrap off a load of good working bits.

Yes, VWZ AI. Is connected to the HP via the two-wire bus. Does the HP-specific stuff, the SensoComfort controller is generic for all Vaillant htg systems inc boilers and hybrid/mixed. The manuals are not very helpful for understanding but this FB forum is your friend. Just keep an eye on it, most common topics get a fresh airing once a week or so. Also lots of resources in the Files tab, manuals, performance graphs etc. Unless your installer is really expert you will after a short while be able to tweak the settings to suit your circumstances and get better perfomance/lower electricity bills. Record what it is currently set to first! There is also a SensoComfort simulator here which will allow you to play without changing your real settings.

I wondered if there was any remaining value in the original paperwork, but between my installing the battery system and applying for a heat pump WPD had been taken over by NG and the process seems to have changed quite a bit. A phone call might swiftly elicit whether it can be re-submitted or you are better off starting again. Or you might be put on hold for 40 mins...

How would this help?

You can certainly do it yourself (I had no choice as the battery system was a self-install) but it is by no means straightforward so if the installers are willing I would leave it all to them, hopefully they deal with yr DNO all the time and know the wrinkles of the process. There are (or were) several different kinds of application possible, some fast-track and some not and the forms vary from one DNO to another so getting the correct advice is not easy. If nevertheless you are in a big hurry I would start with a call to yr DNO helpline and ask what they want rather than try and work it out from the web site.

In that case give them a choice, either they give you permission for angled frames - which will cost extra and look dreadful - or allow you to have a normal pitched roof. PVGIS is your friend here as you can demonstrate to them how much generation you will sacrifice.

In the article linked to above Michael Podesta shows that without a boost phase you might save 12% but the recovery time is impossibly long. He suggests that you need 6kW boost power (where the steady-state is 3kW) to get a recovery time of 3 hrs and this reduces the savings to 9%. Also if the CoP falls from 3.0 to 2.5 then the savings are more than wiped out. Clearly if the OAT is such that you do not have 100% overcapacity to play with you cannot do this, and in the limit you dare not have any setback at all or you can never recover. Otherwise you will have to choose which rooms you can heat at any one time.

Well IMHO the scenario where you allow the temp in the A (not set back) rooms to sag proves nothing. Sensible people will (for any specific room) already have chosen the lowest setpoint they are comfortable with, bearing in mind likely activity and clothing level. This by definition means they will detect sag and so not tolerate it. Certainly in the detached house example I would not be happy with a sag of 1.9K I would argue that the only rigorous comparison is where you have "stiff" temp control of the A rooms. Your model shows that in this scenario the "bad setback" highlighted by Heat Geek does in fact occur. The key point is the relationship between CoP and flow temp, you say "Raising the flow temperature reduces the CoP (coefficient of performance) of the heat pump (with data points from a real device) by a greater factor than the heat demand reduction caused by the TRVs, thus the electricity demand of the heat pump goes up while the two rooms are set back." I would be interested (since you do not say) what the "real device" was, whether it has R32 or R290 or some other refrigerant, and how sensitive the result is to choice of heat pump manufacturer, can you comment on this? That is all for yr steady-state analysis. With whole house night set back the likely potential savings are of the order of 8% as discussed a bit here. But as @JohnMo says, having to play catchup moves the HP onto an even worse point on its CoP diagram than required just to combat the "bad setback", this will be a bigger effect but as Michael Podesta has demonstated the overall result is, "Well, it depends, but it’s marginal, either way". The only getout I can see is to do it on cheap rate electricity and this will I hope give a net positive result as the savings are partly at normal rate but the boost phase will all be cheap.

Do you have the TS already? If so you could perhaps find corrugated pipe which has more surface/unit length. If not then Newark are quite flexible in quoting specials to order, talk to Adam Blanchard. They might also do you a corrugated coil on its own. @JamesPa has a spreadsheet for performance vs coil size in DHW tanks, it should also work in reverse for HW coil in TS.

Ah, so ideally you need rads which are big enough to cope also with the heat leaks to the setback rooms. Yes we are getting 6 rads changed for bigger ones, required uplift factor 1.9x. In one of the study/bedrooms this is not quite achievable bc of furniture but fitting foil and having it plumbed TBOE will help a bit. Your paper concludes Using common open-loop weather compensation (radiator flow temperature driven by external temperature only) eliminates the bad setback effect, and indeed saves a little extra energy. This is in return for a small sag in temperature for A rooms, though likely well within tolerable bounds. But this doesn't really eliminate the bad setback effect. If the "small sag in temperature" is "tolerable" then you could turn the setpoint/WC slope down by a corresponding amount all the time and make even greater savings! To respond to what @JohnMo has just posted, we have already got the wireless TRV setup so it is a question of optimising how to use it. I certainly wouldn't be fitting it from new when installing the heat pump. But it does allow flexible zoning by time and temperature and this will I think be useful. As a specific example I envisage using the UFH to heat the living room 18/24 to a setback temp of say 16C, there are also rads which will quickly bring it up to 20C at 1700 using off-peak heat from the thermal store. The ceiling is very leaky so this will provide the two bedrooms above with background heat as well. Only when they are in use for guests will they be heated to 18C, I cannot think that heating them all the time will save money. Verifying all this experimentally will be very complex when I also pose the question Will Octopus Cosy with its 3 periods at 10p/kWh be better than Octopus Intelligent Go with a single 6 hours at 7p plus whatever is achievable by gaming their algorithm by playing with the EV charging times?

Following this with interest. @DamonHD you mention radiator (over) sizing as a complicating factor but I did not see any conclusion about the magnitude or sign of this effect, can you enlarge on this point for me? I would love to see the work extended to the savings (or otherwise) of whole-house night setback. @JamesPa has done some modelling of this which IIRC showed real but modest savings from the heat losses being somewhat lower. Again there is a "bad setback" effect if the HP has to work hard to re-attain the daytime temps in a reasonable time. But I am guessing this may be reduced or eliminated if it happens only inside a cheap electricity window. We have a two storey long thin 180 sq m barn conversion with various unusual occupancy patterns. In particular the middle two bedrooms are used mainly as studies in the daytime, and the fourth only when we have guests. But the living room (which occupies half the ground floor) is only used in the evenings. There are Honeywell wireless TRVs on nearly all the radiators and I am considering how best to incorporate these into the control strategy for the 12kW HP which is shortly to be installed. Initial approach will be to simply use them for overheat prevention while I get the weather comp optimised first. After that it may depend on my patience for carrying out meaningful and detailed experiments!

I think diversity will become less applicable and this will give them tremendous problems in future with all sorts of heavy loads switching on at the start of the cheap periods. It is not like not using all four cooker rings at the same time, everyone is going to set their home battery, EV charger and HP to kick in at the same time. 10 mins (or even 30 mins) of programmable dither is not going to make much difference. In my case that will be 67 amps out of my permitted 80 all at once. The DNOs don't control which supply companies the punters are signed up to, so the small variations between them in the cheap period timings aren't going to help much either. I forsee OFGEM having to step in to enforce more variability in them. Silly, if they are nominally going to restrict you to 12kW then logic dictates that they should fit a 60 (or 50) amp company fuse.