@technogeek 

Floating Earth??

I would Not be surprised if the Mains wiring , like everything else, was wrongly installed.

Hi @technogeek

Floating Earth?

I have to say that I have never heard of a floating earth!

I have inspected the neutrals, measured the mains but can find nothing untoward.

How, and where , would I Measure a Floating earth?

As with every other "forgotten " part on my Heat Pump the Thermostat Mains wiring was modified and re-installed some three weeks after the start of the "installation".

I would Not be surprised if the Mains wiring , like everything else was wrongly installed.

Please do not be put off from producing "possible" Explanations .

I Do appreciate your input.

I am reaching the desperate conclusion that I must replace the "Now available" Samsung Heat Pump Control board .!! 

@iantelescope no not floating earth, floating neutral ie the return wire from the pump. If its not connected properly the return current has to find a different path possibly through your test equipment. As I said I am probably barking up the wrong tree but it is worth checking the wiring (which it sounds like you have done). You may not have a faulty board because its producing a waveform just not to a zero voltage for the low period of the waveform. It seemed odd that when you put a load on the board (the pump) the waveform pulls up to the voltage rail. With a fault I would not expect any waveform output with or  without a pump connected. Just a thought.

Regards

@technogeek

Sorry for the senior moment , I meant floating neutral!

I have never heard of floating neutral but have certainly experienced Earth loops , and floating earths , where the Source Earth is different from the Destination Earth.

I have tried the constant  B1 , B6 Neutral Live pair in preference to the switched B7 , B8 supply many times over the last year without success.

My PWM  Pump Control

I will have to rely on my Arduino to replace the Samsung Control PWM output.

My version of the Samsung PWM uses sensors attached to the input  ports of my Heat Exchanger in preference to the out and return water ports used by Samsung.

I am able to control and reduce the Water flow Rate by increasing the Pulse Width from 0 to 64 us. Above 64 us the Samsung generates Low water rates with  E911 Errors !

When switched OFF, with a o us Pulse Width,  the Heat Pump sometimes generates high water rates with  E912 errors!

Ironically , I can remove both  E911 and E912 errors using the Relays AND the PWM system together !

many thanks

@technogeek  & @derek-m @Mars

!!STOP COP !!

MY AVERAGE REAL COP IS 2.0 .

With the second anniversary of my SAMSUNG HEAT PUMP FIASCO I can , perhaps reflect on the experience:

My REAL COP , REAL coefficient of Performance, that as measured at the start of my Radiator Circuit, 

MY AVERAGE REAL COP IS 2.0 .

The COP as calculated at the output of the Heat Pump itself is 3.03 !!!

BOTH MEASUREMENTS AVERAGED over the past year.

My "installer " has been STUCK OFF Multiple times , only to be re-instated by the MCS.

The NIC have stated that ...........................................

"WE KNOW YOU ARE NOT GOING TO LIKE THIS ..................BUT NOTHING CAN BE DONE"!

The NIC ALSO SAY THAT "it was not us who re-instated your "Installer " " ........................

implying that my "installer" was re-instated by the MCS .

@technogeek 

SAMSUNG EARTH / NEUTRAL/ Problem

My PWM Reference pin has a 14.7  VAC voltage with respect to both earth and local Mains Neutral.

A 14 VAC Offset around the PWM driving circuit ,  starting at the PWM Reference , going to the Grundfos motor and returning to the PWM Signal would produce havoc !

Any ideas ??

Many thanks in advance

@technogeek 

Floating SAMSUNG  Power supply ?

Should I connect  the o V on my SAMSUNG Heat Pump to Earth?

My O volts has , currently , a 14.7 VAC voltage difference with respect to Mains Earth and Mains Neutral.

My Mains Neutral has a 0.3-0.6 VAC with respect to Mains Earth.

My Grundfos PWM Motor fails when connected to the SAMSUNG PWM Port.

My Grundfos PWM Motor works perfectly  when connected to a Arduino producing  a valid PWM signal.

Please don't advise that I contact an Qualified Electrician.................I have had enough of  Professionals !

@iantelescope

Posted by: @iantelescope

↑

Should I connect  the o V on my SAMSUNG Heat Pump to Earth?

My O volts has , currently , a 14.7 VAC voltage difference with respect to Mains Earth and Mains Neutral.

Absolutely NOT! The only parts of the system that should be connected directly to earth are exposed metal cases and metal motor housings. If you make this connection you will trip your MCB / RCD's etc.

I was merely suggesting you check your neutral connection is good back to your Samsung board and the correct terminal for the neutral has been used which you have suggested you have already done.

That 14VAC you are measuring is possibly the potential difference between the generator neutral and earth. Your voltage measurements should be referenced to neutral not earth.

I have nothing more to suggest to verify if this is a fault or not so you are going to have to set up your flow rates to the correct levels using your Arduino's and figure out how to switch the pumps on and off in sync with the heat pump. Once your radiators, flow rates etc are set then configure your heat curve to adjust the flow temperatures for different times of the year. All this has been spoken about in previous posts.

We need to start making progress in resolving this as I, like other people have a busy life and cannot guarantee I am going be able to continue having an input to this thread sorry.

Regards

Posted by: @iantelescope

↑

@technogeek 

 

SAMSUNG EARTH / NEUTRAL/ Problem

My PWM Reference pin has a 14.7  VAC voltage with respect to both earth and local Mains Neutral.

A 14 VAC Offset around the PWM driving circuit ,  starting at the PWM Reference , going to the Grundfos motor and returning to the PWM Signal would produce havoc !

 

Any ideas ??

Many thanks in advance

 

 

 

 

I would suggest that you do not get too concerned about controlling the speed of your water pumps.

The primary reason to vary the speed of a water pump is to try to maintain a reasonably constant DT at the heat pump and across the heat emitters.

As you found previously, lowering the water flow rate caused the DT to increase, but I doubt that it had much effect upon the quantity of thermal energy being transferred from heat pump to heat emitters.

You may find that with your system a moderate flow rate on both sides of the PHE should allow adequate transfer of thermal energy under most operating conditions, with an increased flow rate only being necessary under particularly cold weather conditions. The DT will vary with heating demand, but should not cause undue problems.

@technogeek & @derek-m

IS the PWM Control on my GRUNDFOS MOTOR FAILING ?

Sorry, @Technogeek , I  intended No offence.

Please accept my apologies for my Scots Blunt Frankness.

I have been here before , so please accept my apology in advance ! I intended No offence!

Earthing the PWM  Reference pin on my SAMSUNG

The installation instructions for my Grundfos pump contain the following Circuit Diagram:

Note that the Return is supposed to be Earthed through the Grundfos Motor PWM interface itself.

The ZERO Volt line on the SAMSUNG is supposed to be Earthed through the PWM motor interface.

My Heat pump PWM Reference, connected to the Power supply Zero volts,  is consequently NOT Earthed .........................but should be..

STATUS ON Samsung Heat Pumps:

The Grundfos Motor can return it's current STATUS  :

Given that my , and I suspect every other Samsung , does not use the returned STATUS,  I , or anyone else , has NO Way of Knowing if the PWM System is Working .......or FAILING!.

In fact, my PWM System is FAILING in that, ultimately,  my Water flow rates are Not altered when the SAMSUNG PWM is used !

Incidentally, The green LED on the Grundfos motor does not change in frequency when working OR NOT!

MY Arduino

My Arduino , running at 4 KHz shows a dramatic increase in the Oscillation rate of the PWM Grundfoss green indicator.

My Arduino is working , changing the water flow rates , the SAMSUNG PWM is NOT.

Failure indication :

The Absence of Motor Status indication is troubling ...................................

HOW DOES ANYONE KNOW IF THE GRUNDFOS MOTOR IS WORKING OR FAILING ?

SAMSUNG DT Control

For optimum heat transfer across my Heat Exchanger my Delta_t should surely be controlled on BOTH Sides of the Heat Exchanger .

A working SAMSUNG ,without a Heat Exchanger should ,presumably,  supply a Delta_t of 5 C between 50 %( or 70%) up to 100% of the Water flow rate.

I am currently rebuilding the Arduino to provide Delta_T control on BOTH Sides of the Heat Exchanger to meet the SAMSUNG Specification under 4051.

....Many thanks .........No offence intended ...............

Posted by: @iantelescope

↑

Sorry, @Technogeek , I  intended No offence.

No offence taken my friend I was just very concerned at your suggestion to connect the neutral to earth in your system 😀

I am also concerned time is marching on and we are not making progress. Winter will soon be on us again especially up your neck of the woods.

As @derek-m has said do not get to concerned about your water pump speed control. It is only to maintain a delta T of 5 at your heat pump. If you set both pumps to a constant speed with your Arduinos to obtain approx 5 degrees in your water circuit and ensure your radiators are balanced we can move forward to the next step, ie controls.

As the hydraulics are part of the forward control loop we have to ensure that is working optimally

Regarding your Grundfoss questions I will get back to you soon

Regards

@technogeek & derek-m @Mars

PWM OR RELAY ?

BS7593:2019

Should the Water Pumps on my SAMSUNG HEAT PUMP  be Regulated , and SWITCHED ON and OFF , by a Pulse Width Modulated Source as shown in case 1 of the Installation manual?

OR ( EXCLUSIVE OR)

Should the Water Pumps on my SAMSUNG HEAT PUMP  be  SWITCHED ON and OFF  by the RELAY System as shown in case 2 of the Installation manual?

RELAY RELIABILITY:??

A visiting French SAMSUNG engineer advised that my  SAMSUNG RELAYS would "quickly" burn out because of the excessive switching currents!

The French SAMSUNG engineer further  advised that the additional relay , as shown in the amendment  to the case 2 of the installation be fitted.

He did not , however, fit the additional Relay himself.!!

The French SAMSUNG engineer further WARNED of the damage caused by the EXCESSIVE INRUSH CURRENTS TAKEN BY THE CAPACITIVE GRUNDFOS MOTORS!

PWM Replacement for Relays.

With the Motor AC Power continuously ON the PWM System SWITCHES the AC power ON and OFF, without Sparking or Relay Burn out !

The PWM System ALSO  controls and Regulates the Water Flow Delta_t .

Why are SAMSUNG STILL using  Relays in the 21st Century?

BLACK INK BS7593:2019 Water !

My Pipe Water has , again, turned to a JET BLACK Condition , totally failing BS7593:2019 .

I will perform my annual pipe clean out using FERNOX  F3 cleaner.

I will then use FERNOX F1 Protector on BOTH WATER CIRCUITS.

The £600 Bill last year to have the pipes cleaned to BS7593:2019 Specification was excessive !