hi Trystan,
Many thanks I will have to investigate further into the differences between the Sontex and the Sharky.
My feeling is still to go with the Sharky with the metal case and 1.5 metre extension cable.
But, I am aware of the difference in the Specific heat of water with and without Glycol.
Let me scan the internet for answers!
ian
Hi Trystan,
I am still trying to get a Water power meter that is “in stock”!
The very popular Sharky is , so far completely out of Sock.
I would prefer a meter with 230 VAC and a low pressure drop of circa 400 m bar. with an extension lead of at least 1.5 M allowing me to see the display above my floor boards.
I would prefer that the device be compensated for the Specific heat of water + Glycol, but would accept the 4% inaccuracy if need be.
Water meters seems to be selling like hot cakes!
ian
Hi Trystan Glyn,
First of all many thanks for your help and advice.
PWM motors on SAMSUNG Heat Pumps?
My SAMSUNG Heat PUMP was supplied with Two expensive Grundfos UPM3 FLEX Motors.
These Grundfos Motors come with PWM controls.
My SAMSUNG Control PCB is fitted with PWM outputs to Drive the supplied motors.
However, the PCB is not connected to the Motors.
My contacts with SAMSUNG say that the PWM system was installed to improve efficiency but did not, in practice, improve the efficiency.
On reading the complete specification for these Grundfos motors it appears that the motors have optical feedback giving the actual flow rate delivered by the motor.
Why do Samsung , or any other Heat Pump supplier, not use the returned flow rate from these PWM Motors ?
Fitted with a temperature probe the PWM motors would return the total Water Power output ?
ian
Hello @iantelescope we’ve got the Sharky 775 2.5m3 230VAC MBUS output in stock and have Sontex meters arriving next week. Feel free to email us at [email protected] if you are interested in either.
Interesting, I was not aware of that, that could certainly be useful!
I assume it’s this part of the datasheet that you read?
It would be really interesting to compare the accuracy of using this vs a heat meter and given how common these pumps are perhaps we can test this. I assume @glyn.hudson’s got this pump with his samsung so I will see if we can look into this here!
Hi Trystan,
On trying to get ( afford !) a water flow power meter this week I stumbled upon this statement from Grundfoss motors. I though that this might be a way of saving on the cost of a meter!
However , This is only an option on demand and is not available on my current motors! Also, Samsung do not use these returns
I have just received a email from the RECC saying that the RECC will restart an application to the NIC to have my “installers” struck OFF for a third time!
But after 9 months I am beginning to lose patience and will have to bite the bullet and remove the heat exchanger, 50 l tank et al myself.
ian
FWIW specific energy density isn’t the only effect @TrystanLea. Glycol also increases the speed of sound in the liquid.
The Sharky isn’t out of stock. Certain distributors might not have ordered in anough of them but there’s nothing like the shortage of supply that the industry experienced during the pandemic.
Main distributors for UK / Ireland as below. Others are resellers.
Stockshed Ltd
Stoneycroft House
Mud Lane
Eversley
RG27 0QS
United Kingdom
Contact : Adrian Page
Tel : 0800 193 3200
Email : [email protected]
Sycous Ltd
46 The Calls
Leeds
LS2 7EY
United Kingdom
Contact : Luke Chambers
Tel : 0113 4575 536
Email : [email protected]
MWA Technology Ltd
2 Wharton Street Industrial Estate
Wharton Street
Birmingham
B7 5TR
Contact: Dennis Hirons
Tel: 0121 327 7771
Email: [email protected]
(Ireland) - Cully Automation
Building 1 Kildare Innovation Campus
Barnhall Rd
Leixlip
Co. Kildare
W23 Y972
Ireland
Contact: Shane O’Regan
Tel: +353 1 601 4012
E-mail: [email protected]
FWIW if you specifically want a DN20 (130 mm x G1" flow sensor body) Sharky 775 with 230 VAC and you don’t care for it to be new-new then there are shedloads of them available from a large job back in 2015 that somebody mis-ordered.
e.g.
Danfoss Sonometer 1100 = Diehl Sharky 775 in a different frock.
Those will come with both mbus cards and pulse output cards if they’re from the job I suspect they are.
(I picked up a bunch for £50 apiece…because I needed the m-bus cards…then gave away the meters themselvs on LinkedIn a while ago)
The Kv value on that will be 5.48 or 3.3 kPa at 1000 litrre/hour. Perfectly fine for a little heat pump. Those 775s you can read as often as you like on 230 VAC or every 5 mins on battery.
They aren’t heating/cooling meters though so won’t be accounting for the energy shunted back out of the hosue during startup/shutdown/defrost.
Hi Marko
Many many thanks for your excellent input …I stand corrected …the Sharky is readily available.
No excuses , my fault.
ian
Hi Trystan,
Given the resumed interest by the RECC/NIC into my “installer” I must quickly measure the actual output Energy/Power in the water pipes.
To save money I would use the much cheaper M Bus not, unfortunately, the Mod-bus.
Should I use a direct PC Serial port OR an Arduino acting as master?
On accessing the “PI Hut” your good name came up as an “Awesome” source of information about the relative merits of the M Bus and the MODBUS.
The visiting SAMSUNG engineer provided greater insights into my SAMSUNG heat pump, not all of the insights complimentary to SAMSUNG.
For example, the SAMSUNG Engineer pointed out the use of additional relays to "protect " the standard motor relays from burnout. ( see page 23 of the Samsung Control kit manual).
The Additional relays are “required to increase motor power and to protect the PCB Motor relays from burnout caused by the large startup inrush currents often in excess of 10Amps!”.
Given my ferocious multiple motor oscillations…
…I do not expect my Relays to survive until new year!
I need to stop the “oscillations” now apparent on my secondary water loop!..surely without another 50 l tank!
If tanks on BOTH Primary and Secondary water loops are required then a return to the idea of a shared common Water tank would be required?
Why use Relays anyway ?.. and then use yet more relays to cure this …optically isolated zero crossing triacs would surely be more reliable!
ian
Yes, that’s the same pump that I’ve got. Happy to do some tests.
Your UMP3 won’t be getting close to 10A. I’ve also got a UPM3 and at max power it uses less than 0.3A. According to the datasheet your UMP3 has a max inrush current of 4A, however since Samsung is controlling the pump via PWM the inrush capacitor in the pump will be permanently charged resulting in zero inrush current when the pump is cycling and the heat pump is switched on.
Hi Trystan,Glyn
Grundfoss Motor surge currents!
The visiting SAMSUNG engineer emphasised the point that the Grundfoss motors present an initial Capacitive load.
The initial capacitive load of the Grundfoss motors is “initially” charged with a large surge current in excess of 10A Amplitude.
As the SAMSUNG Engineer emphasised these initial surge currents burn out the contacts on the relays mounted on the PCB .
The Grundfoss motor manual , page 50, warns about driving these Capacitive motors from relays.
As the SAMSUNG Engineer pointed out the relays do burn out under the large inrush currents.
The SAMSUNG engineer specifically pointed to the addition of another , relay as shown on page 23 of the installation manual.
Surely, if switched ON/OFF at the ZERO point of the AC mains the motors and switches would be protected?
Surely , a ZERO Crossing optically isolated TRIAC would be more appropriate!
The obvious answer would be use of the PWM Motor controls …but the SAMSUNG engineer became very reticent about the performance of the PWM motors.
I gather that , you, Glynn have some further experience with these “extant but unused PWM drivers”.
ian
This isn’t exactly news. It happens. The relay contacts need to be made of a suitable material and suitably rated. I suspect size and cost might have had a excessive influence on the choice of relay.
Unfortunately not. While it helps significantly, the inrush can last many mains cycles while the motor gets up to speed and the magnetic fields stabilise.
Again, like the relay, the triac needs an adequate I²t rating so that it too doesn’t burn out during the inrush period.
Hi Robert, Glyn, Tristan
Again, Robert, many thanks for your knowledgeable expertise!
It certainly looks that the primary requirement that SAMSUNG made in their design was cost.
However, the suggested SAMSUNG solution to the problem of burnt out relay contacts is the provision of another , larger relay, in series with the first relay!. See page 23 of the SAMSUNG CONTROL Manual
A far better solution would be the continuous use of 240 vac to the motors but controlling the speed using the PWM input controls.
My Control board is fitted with the PWM inputs as shown on page 22 of the control manual
However, The PWM controls on the motherboard are not connected to the supplied PWM motors !
The Visiting SAMSUNG Engineer was very reticent about the extra cost in supplying PWM motors and then not using them!
The Engineer then gave an in depth demonstration on how to connect the PWM Motors to the PWM driver on the Motherboard.
The SAMSUNG Engineer was shown a graph showing the excessive motor switching.
The SAMSUNG engineer commented that "the Excessive motor switching will damage the relays , and the motherboard PCB .
I will try the PWM Motor control system , but with some considerable trepidation!
ian
Hi Tristan,Glyn et al,
I have now tried the PWM motor driver on my SAMSUNG Heat Pump.
The PWM signal is ZERO…PWM does NOT Work on a device produced in 2021.
Given that the PWM drivers Do Not Work , I am beginning to suspect that these SAMSUNG Motherboards were produced within COVID.
Certainly , the fact that the PWM motor driver does not work is , yet another disappointment , YAD !.
ian
PWM is certainly used if the PWM control cable is correctly connected. I’ve just done some testing on my Samsung ASHP UMP3 pump. The pump is not controlled by the relay, it’s controlled via the PWM input. The relay is always closed (240V always present) and the pump is stopped and stared via the PWM signal, therefore the inrush capacitors will always be charged as long as the heatpump controller is powered. You can check to see if the PWM signal is active on your pump by looking for the green flashing LED. If you see this LED flashing then the pump is in PWM mode:
Hi Glyn,
When used and working , the PWM Green LED should oscillate at 12 flashes per second.
When NOT used and NOT Working , the PWM flashes at 1 Flash per second…
My LED shows no PWM signal.
ian
Hi Glyn,
My visiting SAMSUNG engineer could not explain why the PWM driver does not work on many SAMSUNG Heat PUMPS.
He, himself, could not get the PWM motor driver to work.
That is the probable reason that the Motor(S) are still destroying relays, and that the in series Relay shown i on page 23 of the Samsung manual should be implemented.
ian
