my cook top hates my heatpump?

[inductive]

good evening (if its evening where you are )

so. i've got a fun one on my hands here. as stated in the subject. my induction cooking top won't work when the compressor of my heatpump is running.

which seems a bit odd to me. have anyone ever encounter something like this before?

its only the cooker that stops working. all other electronics is working normal (almost, i can hear the compressor running in my desktop computer, some electical noise that starts and stops with the compressor)

the fun part for me is that the manufacturer of each units blames one another. so i'm stuck with this problem.

the cooker is about 4 years old. and the heat pump is about 1 year old now. and it started when the heatpump was installed

could the pump send back electrical noise?


the cooker is a GRAM induction one. and the heatpump is a 16kw Daikin Altherma LT split (air to water) heatpump. PWM controlled. so it produces heat after demand, and not on/off as other pumps often are

damn problem is driving me nuts. turning of the heat everytime i'm using the cooker is starting to get old

oh. the electrical is 230v IT single phase. (rural norway)


all hints/tips are welcome

[KaneTW]

That sounds like the compressor generating a boatload of EMI.

[andy3055]

How far is the compressor from the cooker? is there anyway you can add some space (probably not)? Could you put them on different circuit breakers (if they are on the same breaker in the panel)?

[inductive]

That sounds like the compressor generating a boatload of EMI.

yes, but should it? should a $20k heatpump be this noisy?

How far is the compressor from the cooker? is there anyway you can add some space (probably not)? Could you put them on different circuit breakers (if they are on the same breaker in the panel)?

hmm. about 10meters or so. the compressor is outside, on the wall

[hermit]

my induction cooking top won't work when the compressor of my heatpump is running.

(almost, i can hear the compressor running in my desktop computer, some electical noise that starts and stops with the compressor)

it started when the heatpump was installed

Was the heat pump a replacement item or an addition/change over?  Did you have an AC unit that didn't do this?  I'd think a 4 year old induction cooker would be adequately filtered for normal conditions.   These are the kinds of problems that popped up 30/40 years ago that delayed electronics being introduced more quickly.

[andy3055]

That sounds like the compressor generating a boatload of EMI.

yes, but should it? should a $20k heatpump be this noisy?

How far is the compressor from the cooker? is there anyway you can add some space (probably not)? Could you put them on different circuit breakers (if they are on the same breaker in the panel)?

I would look for electrical separation up to the panel like I mentioned before.

hmm. about 10meters or so. the compressor is outside, on the wall

[JustMeHere]

You might want to check your grounds.   Make sure your AC ground is good back to the panel.    A ground loop could cause problems.   If you have an AM radio you can plug into your stove's circuit, see if you hear any more noise when the AC is running. 

[Tomorokoshi]

Conducted emissions EMC tests through the AC power line are typically run from 150 kHz to 30 MHz. As mentioned above, a multi-band short-wave radio can easily pick up this kind of interference.

Even though you are in Norway, it's likely that both units are CE marked and therefore would have been tested and passed applicable EMC tests. However, those tests are in isolated conditions, and it's likely that some part of your installation is not the ideal case used by the manufacturer when the tests were done.

If your home is far away from a power station you may have relatively high impedance for your power lines. This would make the switching currents drop the voltage, which is how the conducted emissions will cause the two units to interfere with each other.

Electrically it's possible that the control circuit for the unit is measuring the line voltage or system current, and the interference causes a control fault even though the power electronics might be able to handle it. There isn't an easy way to tell, and there isn't much that could be done anyway.

Thinking about the stovetop its frequency is likely above 20 kHz to keep it out of audio range. However, the motor control will have some component that is low enough to hear.

It's an interesting problem that could require some sophisticated equipment to track down.

[Monkeh]

You might want to check your grounds.   Make sure your AC ground is good back to the panel.    A ground loop could cause problems.   If you have an AM radio you can plug into your stove's circuit, see if you hear any more noise when the AC is running.

It's an IT system. I'm not experienced with their installations, but there may not even be a ground.

[Siwastaja]

Due to all legislation and regulation, things like this are surprisingly rare nowadays.

Note, the legislation requires limiting both the emission, and susceptibility. So the problem can be either one: maybe the heatpump emits way too much noise. Or maybe the cook top is way too oversensitive to the small, allowed amount of noise.

There are three possibilities:
1) The heat pump isn't compliant,
2) The induction cook top isn't compliant,
3) Both are non-compliant

It will be very difficult to guess which it is. One would need to perform proper EMC measurements for both units.

Furthermore, because of the regulation, it's very well possible the units are properly designed, meaning the original prototypes (and possibly a few units out of a manufacturing batch) pass the tests, but you are seeing a unit failure. Think about a loose shielding connection inside either unit.

A house wiring problem can make the problem worse, of course.

[GerryR]

You might want to check your grounds.   Make sure your AC ground is good back to the panel.    A ground loop could cause problems.   If you have an AM radio you can plug into your stove's circuit, see if you hear any more noise when the AC is running.

I'm with JustMeHere; my bet is on bad grounding.  I had a friend that had a separate panel put in a room for a washer and clothes dryer.  When using the dryer, the kitchen stove and oven did strange things.  When I tested between grounds, there was a major voltage difference.  Once I tied the grounds together back in the panel, the problem went away.  These were 220 VAC circuits.  Just a guess.

[inductive]

Was the heat pump a replacement item or an addition/change over?  Did you have an AC unit that didn't do this?  I'd think a 4 year old induction cooker would be adequately filtered for normal conditions.   These are the kinds of problems that popped up 30/40 years ago that delayed electronics being introduced more quickly.

heatpump was bought new, as a replacement for an old oil-furnace from 1970. never been AC in the house (don't need much, its winter here 10months of the year)

You might want to check your grounds.   Make sure your AC ground is good back to the panel.    A ground loop could cause problems.   If you have an AM radio you can plug into your stove's circuit, see if you hear any more noise when the AC is running. 

good call. that is something that should be tested.

on a side note. the powerwires for the heatpump (both indoor unit and outdoor unit) are both new, installed when the pump was installed. however, the powerwire to the cooker is the old one from 1979. (3x4mm2, 20A breaker)

I'm with JustMeHere; my bet is on bad grounding.  I had a friend that had a separate panel put in a room for a washer and clothes dryer.  When using the dryer, the kitchen stove and oven did strange things.  When I tested between grounds, there was a major voltage difference.  Once I tied the grounds together back in the panel, the problem went away.  These were 220 VAC circuits.  Just a guess.

i've only got one panel. all grounds are grounded to the same lug. which then has a wire going outside to a "ground spear" which is buried into the ground

It's an IT system. I'm not experienced with their installations, but there may not even be a ground.

i believe norway is among the last countries that still uses IT. and its prone to have grounding issues.. however none of the RCD's have ever tripped (RCD in every breaker)

and another sidenote. most outlets are ungrounded. only basement outletes/kitchen/bathroom are grounded. rest is ungrounded. but they don't cause me any trouble

[Jeroen3]

An RCD won't trip in an IT system. That's the whole advantage of the IT system.
Very nice for high continuity. And very bad for noise if the impedance of the transformer is high.

Go rent a power harmonics meter and measure what you got.

[ogden]

What is nominal power of your mains feed? 16KW (!) pump is quite a load load for single phase rural power line. First obvious thing to do - measure AC voltage while pump is running.

[Monkeh]

What is nominal power of your mains feed? 16KW (!) pump is quite a load load for single phase rural power line. First obvious thing to do - measure AC voltage while pump is running.

16kW heat pump. That's the heat transfer rating, power consumption should be just over 4kW, maybe edging over 6kW in the worst case. Not particularly scary.

[ogden]

16kW heat pump. That's the heat transfer rating, power consumption should be just over 4kW, maybe edging over 6kW in the worst case. Not particularly scary.

Whatever is electrical power of that heat pump - AC voltage droop shall be checked anyway. Could be The Reason.

[Berni]

Yep heatpumps are usually rated for the heat output power in kW (Since that's what you care about) so this is actually all the input power plus all the heat it pulls from the environment. For marketing purposes this number is cherry picked from the best case combination of outdoor and water temperature so will rarely even be reached in practice.

To get 16kW of output it probably needs about 4 to 5 kW of electrical input power. The 4kW number is quite common because 20A circuit breakers are common for heavy loads in households. And this is likely where the problem is, this is a lot of power for a usual residential service and so depending on how good the wiring is this could cause a significant drop in voltage for anything on that phase. To make things even worse induction cookers are also very heavy loads that can consume anywhere from 1.5kW to 6kW or even more, combine the two and the voltage could drop even more and it could be that the induction cooker is the first to throw its arms up and give up when it notices its not getting enough voltage to work.

If you have three phase power available (It is common to have 3 phase in residential here) then the fix is easy to move the heavy loads onto different phases by just moving the circuit breaker in the electrical cabinet. If you have single phase power then there is no such easy fix. In that case i would measure the mains voltage on that phase and see if it is within your governments regulations regarding power quality (Here it is i think -15% to +10%). If the voltage at your mains feed falls outside of these limits then the power company is required by law to fix it. I had to do this once and upon complaining to them they brought there own measurement gear and dataloged the voltage of all phases for a week before saying it is indeed out of tolerance and running a new cable.

EDIT: Also make sure you are within your rated power for your mains service. The oldschool main fuses are quite wide in tolerance so it is possible to pull say 30A on a 25A main fuse. In that case the power company may force you to upgrade to the correct service power and pay more on your electricity bill accordingly before they would do anything about your complaint. Here they fixed the tolerant fuse problem by using the new smart meters to monitor current and disconnect in the event of an overload rather than rely on the main fuses to blow if you draw more than what you are paying to get.

[inductive]

What is nominal power of your mains feed? 16KW (!) pump is quite a load load for single phase rural power line. First obvious thing to do - measure AC voltage while pump is running.

16kW heat pump. That's the heat transfer rating, power consumption should be just over 4kW, maybe edging over 6kW in the worst case. Not particularly scary.

right now i measure 228 volts between N and L on the breaker for the compressor


the pump is a beast, but is only delivered in single phase.

it maxes about 7kw.

but, there is also two backup heaters in the indoor unit (combi unit with domestic hot water). they are set at 3kw each for the time being. but can be set to 6kw each, and the indoor unit has provisions for going 3phase

i do have 3 phase cable into the house, but the last phase is not hooked up. (freggin expensive, both to have done, and the extra montly/yearly costs just bare having 3phase 63A). but at some point this will be done, but not now.


i'l have a look into the voltage leveles over some time

[inductive]

one qick question, what would a normal voltage balance be?


L to Ground: 116,3
N to Ground: 144,7

L+N:  229,4

there are some variatons in voltage. but only 3-4 volts

[noidea]

Just a lowly non Electrial Engineer HVAC tech here but a few comments for the mix.

A 16kW unit is probably on a 30 Amp single phase supply.

I found what I think is the right service manual for your model on the net ERLQ011-016CV3 can you confirm the model number? If it is and the noise is only happening when the compressor in the heatpump is running then it most likely related to the active power factor correction circuit (V2R, V3R, V1T, L1R) section of the A1P board and not the power transistor module thats creating the three phase for the compressor.

I have worked mainly on other brands than Daikin but this style of Inverter power circuit design, with two bridge rectifiers, an IGBT and reactor coil is pretty common if a discrete active filter module is not being used.

If I had to guess I would suspect it is more a conducted than radiated emission issue as you said you can hear some noise on your desktop PC as well. I would guarantee that the AC unit is compliant to the relevant test standards Japanese manufacturers tend to be pretty honest about this, but it will be very tight to the standard.

The IT wiring system is interesting, the A3P board contains the noise filtering circuit and should be bleeding the noise in the unit to ground. In Australia we use TN-C-S and I know from experience faults in the earthing / neutral earth bonding tend to make noise issues worse here.

I'm sorry I can't really offer much in the way of how you actually test this in the field, I would like to know myself 

[noidea]

one qick question, what would a normal voltage balance be?
L to Ground: 116,3
N to Ground: 144,7
L+N:  229,4

This suggests that N is not actually Neutral but another phase, if Neutral was really a Neutral you would expect L-N= ~230vac, L-E=~230vac and N-E=0vac

Again I'm not familiar with IT wiring or Norwegian power but this suggests you may actually have two phase no neutral power supply.
https://www2.theiet.org/forums/forum/textthread.cfm?catid=205&threadid=88103&filtmsgid=581037

[inductive]

Just a lowly non Electrial Engineer HVAC tech here but a few comments for the mix.

A 16kW unit is probably on a 30 Amp single phase supply.

I found what I think is the right service manual for your model on the net ERLQ011-016CV3 can you confirm the model number? If it is and the noise is only happening when the compressor in the heatpump is running then it most likely related to the active power factor correction circuit (V2R, V3R, V1T, L1R) section of the A1P board and not the power transistor module thats creating the three phase for the compressor.

I have worked mainly on other brands than Daikin but this style of Inverter power circuit design, with two bridge rectifiers, an IGBT and reactor coil is pretty common if a discrete active filter module is not being used.

If I had to guess I would suspect it is more a conducted than radiated emission issue as you said you can hear some noise on your desktop PC as well. I would guarantee that the AC unit is compliant to the relevant test standards Japanese manufacturers tend to be pretty honest about this, but it will be very tight to the standard.

The IT wiring system is interesting, the A3P board contains the noise filtering circuit and should be bleeding the noise in the unit to ground. In Australia we use TN-C-S and I know from experience faults in the earthing / neutral earth bonding tend to make noise issues worse here.

I'm sorry I can't really offer much in the way of how you actually test this in the field, I would like to know myself 

2x 32A breakers

the indoor unit is a  EHVH16S26CB9W and the outdoor is: ERLQ016CAV3

and YES. it only happens when the compressor runs

[inductive]

one qick question, what would a normal voltage balance be?
L to Ground: 116,3
N to Ground: 144,7
L+N:  229,4

This suggests that N is not actually Neutral but another phase, if Neutral was really a Neutral you would expect L-N= ~230vac, L-E=~230vac and N-E=0vac

Again I'm not familiar with IT wiring or Norwegian power but this suggests you may actually have two phase no neutral power supply.
https://www2.theiet.org/forums/forum/textthread.cfm?catid=205&threadid=88103&filtmsgid=581037

L1 and L2. but all terminals are labeled L and N on the new stuff as TN is the "new" standard that is being built

[Berni]

Ah yeah you have the weird Norwegian 230V Delta wired 3 phase thing.

For those that don't know about it here is what its about. Most in Europe tends to use a 230V Star 3 phase system so that from each phase to neutral you have 230V and between phase is 400V. But for some reason some places like Norway have it the other way around where they have 230V between phases but as a result only ~130V between phase and neutral. So as a result they have to run 230V loads between two phases much like the Americans get there 220V in there split phase systems that are popular for residential there. This is a problem however if you try to run a 3 phase load as it will not get the 400V it expects, so a step up transformer is required to run those. Inversely if you bring a 3 phase motor wound for this 230V between phases and plug it into regular 400V 3 phase you will blow things up (Tho such a motor should run just fine if you wire it into only delta mode).

As for the imbalance in voltages it should not be too much of a concern. Since this is a delta configuration means there is no neutral wire in the distribution network back to the transformer and your neutral is actually your local earth, this is fine because as far as i know you should not power any loads between one phase and neutral in this system. By the way this delta system is used all over Europe too, but only on transmission lines between transformer substations because it only requires 3 wires as opposed to the 4 in a star configuration that is typically used for final low voltage distribution.

As for the noise, yeah i can confirm heat pumps spew out a lot of conducted noise. They have a 3 phase VFD inside and to get the DC rail for it there is a PFC boost converter. My particular Viessman brand heatpump has a massive mains filter installed inside it right where the mains comes in, but it does still spew out quite a bit of noise. Since these huge IGBT power converters tend to operate at low frequencies <100KHz its possible they have ducked under the conducted EMI regulations and its possible the inductive cooker is especially sensitive to a certain frequency range. If that 229V is with the heat pump running full power then the voltage is definitely stable enough. Also make sure that your induction cooker is wired up properly as i have seen 2 phase connection being quite common with them, but its actually just two separate cookers inside each fed by its own live. This is to allow you to spread the ridiculously powerful 6kW ones across two phases of 3kW or wire the two phases together for single phase 6kW input. Its possible the cooker is just about tolerant enough to work at 130V input but when the heat pump gets going it dips enough to cut it out.

[inductive]

so. what you are saying is that the cooker "can" be internally connected to just ONE of the phases? (splitting one phase to the oven, and one to the induction top?). well. that could be. i don't know. might have to open it up to have a look

but the oven part is working flawless either way. its only the induction top that is having an issue