Sunpentown Mr. Induction SR-964T Induction Cooktop

Ownership: 8 months
Usage: daily for about half a year and seldom for the other half
Price: $73.33 including tax
Value: 50%
Meets Expectations: 40%
Durability: 20%
Appearance: 95%
Recommend this product? No

DESCRIPTION

Results from test of actual power consumption assuming inverter and wiring are 90% efficient while heating water in an uncovered 7.5 inch diameter iron skillet:

mode actual power
100 W 500 W
300 W 630 W
500 W 770 W
700 W 900 W
900 W 980 W
1100 W 1050 W
1300 W 1130 W

On my unit the 100 and 300 W modes consume continuous power, but the manual states that they cycle 500 W on and off. My unit might be malfunctioning. After using it for several months, on 2 occasions I observed the 100 W mode to cycle on for 1 second and off for 3 seconds.

When Mr. Induction is idle (control panel on, fan on or off, coil not energized), the power consumption is difficult to determine because Mr. Induction appears to reflect power back to the power supply. My Trace 2012 inverter draws 68 W but strains like it is powering a 1200 W load. I think the 68 W is mostly consumed by the inverter, so Mr. Induction's idle power consumption might be small when connected to the grid or a sinewave inverter.

The temperature settings both modify the power and cycle the coil on and off to regulate the temperature.

It fries an egg using the 300 W or 350 F (180 C) settings. Frying can be done using 500 W to 800 W of power. Stir-frying might require more power.

Mine is made in China.

The fan runs whenever the induction coil is energized and shuts off about 1 minute after done cooking.

The timer can be set from 1 minute to 8 hours with an resolution of 1 minute.

The control panel is lower than the cooking surface which prevents a hot pot from touching the controls and melting the plastic.

If the ceramic cooking surface cracks, you must dispose of it because water could leak inside short-circuiting the electronics.

As with any induction cooktop you must keep certain objects away from the cooktop to prevent them from being heated or erased.

As for induction compatible cookware, 18/10 stainless steel (18% chromium, 10% nickel) is not magnetic and does not work. 18/0 stainless steel (18% chromium and 0% nickel) does work. The bottoms and sides of All-Clad and Tri-Ply Clad stainless steel pots are made with magnetic stainless steel on the outside, a layer of aluminum above it and 18/10 stainless steel on the inside. Induction cookers produce hot spots on the bottom of the pot which are clearly visible when boiling water in an iron skillet because the bubbles of water vapor form in certain spots. The idea with the expensive All-Clad and Tri-Ply Clad pots is for the heat to be induced in the outer layer of magnetic stainless steel on the bottom, conduct into the aluminum which spreads the heat around the base and sides of the pot, conduct through the layer of 18/10 stainless steel and finally conduct into the food.

Some of the cheaper induction compatible stainless steel pots are made from 18/10 stainless steel and have a layer of magnetic stainless steel and aluminum attached to the outside bottom. Some pots are made entirely from 18/0 stainless steel which are induction compatible, but they are harder to clean than 18/10 stainless steel.

A pan with a thick base also helps to spread the heat around. My two iron skillets are old, thick and heavy, much more so than the cheap, thin-walled stuff I frequently see in stores. My 7.5 inch diameter skillet spreads the heat around well enough for frying. My 9 inch diameter skillet is too cool on the outside parameter to cook pancakes there. If I rotate the skillet, I can cook 3 pancakes huddled in the middle.

While my iron skillets are quiet on the operating cooktop, my Tramontina Tri-ply clad pot hums loudly. On some power settings, usually the 500 W mode, the lid rattles and screeches like when fingernails are dragged across a chalk board. If powered by a sine wave, it might be quieter.

To use an aluminum pot with Mr. Induction:
A. put an induction compatible skillet on the cooktop
B. add a layer of water to the skillet
C. turn Mr. Induction on
D. put an aluminum pot containing water in the skillet
E. As the water in the skillet warms, the heat conducts into the water in the aluminum pot.
F. As the water in the pot approaches boiling temperature, the water in the skillet begins to boil away. If necessary, add more water to the skillet because Mr. Induction will stop cooking if the water boils away. The hottest I could get the water in the aluminum pot was 195 F (90 C).

Having an off-grid photovoltaic system, I am mindful of the power consumption of new appliances. Having the lowest maximum power mode, 1,300 W, of all induction cooktops, this one seemed the best choice. Because I do not want the cooktop to shorten the lifetime of my battery array, I planned to use only the lower power modes. Unfortunately the power modes do not correspond to the actual power consumption. On a sunny day between about 9 am and 2 pm I can use the 100 W to 500 W modes consuming only the power output from my photovoltaic panels. I had to purchase an extra 140 W PV panel to use the 500 W mode following this rule which makes the cost analysis of converting from propane to induction cooking poor. I have managed to do all of my induction cooking using the 3 lowest power modes (500 W to 770 W actual power consumption).

I had another idea to minimize the load on my batteries. I would boil water in the morning on the induction cooktop using the PV power and pour it into a vacuum insulated thermos. I would use this hot water later in the day to make soup, tea or to preheat anything that I would cook in boiling water in the microwave for dinner. I would thereby reduce the load on my batteries when cooking dinner. This idea has worked well. However, the unanticipated problem of having to lower the battery voltage to get the cooktop to energize the coil has introduced an additional load on my batteries. Consequently I am unsure whether or not the induction cooktop has increased the burden on my batteries.

NEGATIVES

1. When operating during the first few days, Mr. Induction emits an odor that reminds me of vaporizing plastic.

2. The power and temperature settings do not have enough resolution for cooking. For example, the 320 F (160 C) mode is not hot enough to brown a tortilla shell while the next higher setting, 350 F (180 C), burns it and makes canola oil smoke. The smoking oil suggests the temperature of the skillet is about 400 F (204 C). A taco cooks best on the 100 W mode to warm it and then switching to the 300 W mode to brown it. The manual indicates the temperature settings have a variance of +-20 F (+-10 C), but I think it is actually larger. The power settings suggest that you can adjust the power over a range of 13 times, but the actual power consumption shows the real range to be 2.25 times which is a very deceptive marketing ploy. Because the temperature settings are basically useless, I cook using the power modes. Note that if the 300 W mode cycled on and off like the instructions describe instead of outputting 630 W continuously, then I would have difficulty frying food because none of the power settings are in the correct range. I can not simmer rice because it will boil over unless I stand there for 20 minutes manually turning it on and off. Given the great variety of factors that affect heat flow out of a pot (ambient air temperature, shape of pot, thickness of pot wall, material from which the pot is constructed, amount of liquid in the pot, lid used or not, pot cozy, vacuum insulation and even the variance of the power modes), an induction cooktop needs an analogue dial or many more low power digital settings.

3. It needs a status light to indicate when the coil is energized because some pots are very quiet. I have to touch the pan or insert my finger into the water to verify that it is heating.

4. The lock feature is annoying because Mr. Induction powers up with it on and frequently activates it automatically.

5. The ceramic cooking surface seems fragile. Be gentle with it.

6. The base of the cookware must have a diameter between 4.5 inches and 12 inches before Mr. Induction will cook. It will not work with my 3 inch diameter magnetic stainless steel measuring cup.

7. When using my cheap 2,000 W modified-sine wave inverter, the control panel operates but the induction coil will not turn on. The cooktop does not like the waveform.

8. Mr. Induction has low and high voltage protection circuits. I have not had a problem with the low voltage one, but the high voltage one prevents the coil from energizing when my battery voltage is above about 13.2 volts. This is a problem because my Trace Inverter does not regulate the peak output voltage. Usually I run the microwave oven for 20 to 30 seconds to drop the battery voltage enough to allow the coil to energize.

9. Mr. Induction has a high temperature cut-off circuit that disables it for about 10 minutes in the middle of cooking ruining the food. This circuit never trips when boiling water and only once tripped when using my 7.5 inch diameter skillet. For some odd reason my 9 inch diameter skillet sometimes trips this circuit even when using the 100 W mode. It is most likely to happen when I boil water and then use the 9 inch skillet on a warm day. Perhaps it has to do with the location of the temperature sensor and the diameter of the skillet. Because it never displays an error message when this happens, maybe the cause is something else. Basically it is unreliable when cooking with my large skillet.

10. Mr. Induction is very finicky about power line fluctuations and other electrical devices operating at the same time. The manual states:

"Plug cooktop in a dedicated 15-amp outlet. Do not share the outlet
with other appliances."

When Mr. Induction is running using any power mode, I get:

A. When I turn on an incandescent lamp anywhere in my house consuming about 60 W or more, Mr. Induction either deenergizes the coil for 1 to 2 seconds and then resumes cooking; or deenergizes the coil, beeps and displays "E0" until I turn off the lamp. According to the manual, Error Code 0 means:

a. Either there is no cookware or no compatible cookware placed on unit.
b. Cookware may be too small or too large for the electromagnetic field.
c. Cookware is not centered on the ceramic plate.

Because none of these conditions are present, it is very confusing what is happening until you learn that the problem is with the power supply.

B. Mr. Induction usually refuses to operate without displaying E0 when my refrigerator is running even though it is on a separate circuit breaker. Note that I said usually because sometimes it will turn on and then shut off while cooking ruining the food.

C. It works okay with my kitchen lights (36 W fluorescent) or the fan in my range hood.

D. It refuses to cook when my computer and modem are running from AC power, but it is happy as punch when my laptop runs from its battery.

E. Mr. Induction throws an E0 temper tantrum when I turn on a blow dryer in my bathroom.

F. It is okay with a drill running until I drill a hole (i.e. put a load on the drill).

G. Mr. Induction emits a clicking sound and refuses to energize the coil when anything it does not like is running in my house.

A competent engineer needs to give Mr. Induction lessons in proper household manners before unleashing him on the world.

[Review continued in next post]

Comments

  • SolInvictusSolInvictus Solar Expert Posts: 138
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    POSITIVES

    1. Mr. Induction is hansom.

    2. The controls are arranged conveniently and are easy to use.

    3. LED display.

    4. It boils water and cooks food faster and using less power and energy than a gas flame, electric resistance coil or microwave oven. The highest power mode is the most energy efficient for boiling water because it allows the least time for conductive heat loss.

    5. My Trace 2012 modified sine wave inverter operates it.

    6. inexpensive.

    7. With this purchase, I relegated all of my propane use to backup applications.

    CONCLUSION

    This induction cooktop has a quirky personality which is bad in a consumer product. It requires too much attention to insure proper cooking when I need to concentrate on preparing other food. Some of the problems are related to my use of a modified sine wave inverter to power it, and it might work better with a pure sine wave inverter that regulates the output voltage. It has satisfied my goal of minimizing power consumption when cooking with electricity but came with deceptive advertising about power levels, power and temperature settings that are too coarse for easy cooking, and a super finicky attitude about not sharing electrical power with other appliances. It has too many sensors making it unreliable for cooking. I recommend against purchasing Sunpentown's Mr. Induction SR-964T Induction Cooktop in hope that there is another manufacturer who makes an induction cooktop more suitable for residential use.
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    you have a defective unit i have one of those, in short one must must have knowledge on induction cooking there are very few cooking ware that would actually work with induction magnet testing helps to identify which may be best stronger the magnetism better the cooking ware(Fyi some cooking ware are alloys as such magnetism may be weaker in some making the ware function-able but not effective).Bottom line i am very satisfied with an exact such unit it does not replace my existing cooking range but complements it greatly when i have enough and extra power form pv system.My unit does not emit a burning smell while it is functioning.It is not nice to do a review about a product with out proper testing. i would admit the unit is not high quality but it preforms decently in my opinion.Please get a good unit and retest making sure you do not exceed your inverter capacity and modified sine wave inverters are not cool for devices that have digital parts(control panel and circuitry on Mr.induction).
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    Also this unit is not a powerful unit you need to compare it gas and electric equivalent to make such comparison
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    fyi also mine operates at full power on xantrex sw2000 with 10cu refrigerator,laptop,modem,router and 32" led tv without any of the mentioned problems,You cannot also put a 9" pot on it since the cooking surface is less that 9"(induction cooking knowledge
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop
    mahendra wrote: »
    you have a defective unit....
    Probably, considering that the 100 W and 300 W modes do not cycle on and off. But I doubt that it is malfunctioning in any other way. It is more likely poorly designed. A unit that is defective, new, right out of the box, indicates non-existent quality control on the part of the manufacturer or distributor.
    mahendra wrote: »
    Bottom line i am very satisfied with an exact such unit it does not replace my existing cooking range but complements it greatly when i have enough and extra power form pv system.
    It is good to know that it works better with a sine wave inverter.
    mahendra wrote: »
    My unit does not emit a burning smell while it is functioning.
    It only emitted an odor for the first few days of operation. There is no more odor. It might have been from a sorbent, perfume or disinfectant. I doubt it was from a burning component.
    mahendra wrote: »
    It is not nice to do a review about a product with out proper testing.
    I am accurately reporting my observations of how mine operates in a real house. I am interested in seeing your measurements of its real power consumption using your Xantrex Prowatt SW 2000. Is my MSW inverter making the real power consumption differ from the power modes?
    mahendra wrote: »
    Please get a good unit....
    How do you know my unit is malfunctioning and causing all of my problems? It's refusal to turn on when my battery voltage is above 13.2 V is not a malfunction because it contains a high voltage shut off circuit which appears to operate correctly. This problem is a consequence of the unit having a narrow operational voltage range and my use of an inverter that does not regulate the output voltage, of which a potential buyer should be informed.

    It states on page 6 of the owner's manual: "Plug cooktop in a dedicated 15-amp outlet. Do not share the outlet with other appliances." Why in the world would it state that given that its maximum actual power consumption is about 1,130 W? There is certainly enough power to share it with a kitchen lamp without tripping a 15 A at 120 VAC circuit breaker (1,800 W). If you read other online reviews, then you will learn there are other people using grid power complaining about it not working when certain other things are running. Some people state it works fine while others say it is finiky. Maybe their power monitoring circuit is unreliable, or does not work well with the large variations in AC power quality, resistance, capacitance and inductance that exist in home wiring.
    mahendra wrote: »
    ... and retest making sure you do not exceed your inverter capacity....
    The Trace Engineering 2012 inverter is rated at 1,400 W continuously, 2,000 W for 30 minutes and 5,000 W surge for 1 second. My battery array is 12 V at 1,580 Ah with about 2 meter long, 4/0 copper cables attaching it to the inverter. It has a big, heavy transformer and what Trace calls "impulse phase correction" which means it reflects reactive pulses back at inductive loads. It starts a 3/4 horsepower air compressor motor on a hot day in June and has no cooling fan. It has a peak efficiency of 96% when outputting 250 W and is 93% efficient at 1,000 W. At the time of testing, my PV array was 750 W. The power requirements of the induction cooktop are well within the specifications of my PV system. Except for it being MSW and more expensive, it is superior to your Prosine. I wish someone still manufactured an inverter as good.

    mahendra wrote: »
    ... and modified sine wave inverters are not cool for devices that have digital parts(control panel and circuitry on Mr.induction).
    A MSW waveform has no effect on the digital parts. Problems occur in some cheap power supplies and with extra hum in audio circuits. Even my cheap inverter with a poor quality MSW waveform powers the control panel and circuitry in Mr. Induction. Mr. Induction simply refuses to energize the coil when using that inverter which is also something that customers should be aware. Campers, truckers and off-griders should be informed about which types of inverters will power the unit. The manufacturer certainly does not test nor warn.

    mahendra wrote: »
    fyi also mine operates at full power on xantrex sw2000 with 10cu refrigerator,laptop,modem,router and 32" led tv without any of the mentioned problems....
    Perhaps the sine wave inverter makes the difference.
    mahendra wrote: »
    You cannot also put a 9" pot on it since the cooking surface is less that 9"
    Page 5 of the owner's manual states, "Base of cookware should be between 4.5 inches and 12 inches." The ceramic cooking surface is a square measuring 10.6 inches on each side. The base of my large 9 inch iron skillet has an outer diameter of 8.5 inches where it begins to curve upward, well within the physical size of the cooking surface and the maximum size specified by the manufacturer. Is my summertime problem with the skillet caused by the manufacturer's specification being false, or is it another quality control issue from China? Any over heating caused by a MSW possibly reducing efficiency would only appear on the highest power modes. I only use the lower powered modes to keep the power consumption within the power output by my photovoltaic array which should avoid any overheating issues. The air blown out of the unit by the fan is never more than warm.

    If you are referring to the uneven heating of the large skillet, it is not a characteristic of induction cooktops in general. It is a characteristic of induction cooktops with a single induction coil, that is, cheap ones.

    There is also that utterly silly rule spouted by the manufacturer to deal with their inadequate design, "To prevent damage to your cookware, do not heat an empty pan." There are numerous foods that require preheating the pan before adding the food. Frying an egg by dropping it into a cold pan does not work because it spreads out too much. The rule that needs to be obeyed is the same for all types of heating: do not over heat your cookware because you might warp thin aluminum, burn off a non-stick surface or whatever. Be a competent cook. Instead the manufacturer is thinking the cook should change his methods of cooking to adapt to the deficient design of the equipment instead of designing a cooking appliance that satisfies the requirements of cooking. Maybe that is the way of Chinese communists: bark stupid orders and expect everyone to obey silently.
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    i agree it is made in china so why expect so much of it
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    i indicated it perform decently considering its price and made
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    another thing mine works fine on high voltages its low voltages it trips on (90-125v measured with fluke dmm).Don't think any thing above that is good for any electronics.As i mentioned it works fine on solar and fine on grid once the voltage is with in range ,with washer on ,re refrigerator on and tv sometime well pump to which has a higher power requirement than washer but not washer and well pump together (all those exceeds my mains breaker capacity)
    I was not trying to be offensive in my earlier post was just trying to add based on observations and usage experience.thank you for understanding.
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    if it helps there is also the burton(about same price of mr. induction) and fagor (around $100) induction cooker which is not different than this although some may deem than as better.Havent seen the burton in action but fagor is the same with a nicer look and YES the are all made in china.Think every thing ultimately,even the stuff marked mde in USA( no offense).They have some part or componet made in china.
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    I intend to use my Mr. Induction until it breaks permanently while waiting for a newer version that has either an analog knob or more digital settings at the lower power end. The NuWave induction cooktop looked good, but it has only 6 power levels and there are so many complaints about the dishonesty of the people selling it, I rejected it. I think the best power levels would be 50 W, 75 W, 100 W, 150 W, 200 W, 300 W, 400 W, 500 W, 600 W, 700 W, 800 W, 900 W and then skip up to some maximum power to boil water quickly. I am not sure how manufacturers could implement temperature modes accurately, but the method they are currently using does not work. They need a better way of measuring the temperature of the pan and a lower power to cycle on and off to maintain the temperature. Electric skillets regulate temperature adequately but not this induction cooktop.

    The owners manual indicates Mr. Induction's operating voltage range is 90 VAC +- 10 V to 145 VAC +-10 V. My measurements show that my unit triggers the E2 error when the battery voltage is above 14.5 V which means my inverter is outputting 145 VrmsAC or 204 Vp. However, the circuit that determines whether the coil gets energized will not turn the coil on when the voltage is 10% above nominal, that is 132 VrmsAC or 185 Vp. I never tested the low voltage cut-off because I would have to discharge my batteries below 11 V which would be bad for them. It is possible the circuit that controls the coil does not operate properly with modified sine wave.

    As for expectation, my 2 burner, propane powered, portable camping stove is more reliable, easier to operate and costs less. However, burning propane emits fossil carbon which I seek to eliminate.
  • mahendramahendra Solar Expert Posts: 141 ✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    that can be yes.good luck
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    I disassembled my cooktop. There are two circuit boards, one under the induction coil which includes the power supply and power amplifier for the coil, and the other under the control pad which presumably handles the controls and timer. The circuit boards appear to have traces and components on opposite sides, are well labeled, are soldered neatly and I did not see any jumpers that would suggest last minute modifications. The induction coil lies beneath the circle drawn on the ceramic cooking surface covering most of the area except the center where the temperature sensor is located.

    jQujLT77PPO9O.jpg
    http://i.minus.com/dQujLT77PPO9O/COOKTOP0.JPG

    When I took the cover off, I found a flaky white power laying around the inside of the unit and covering the temperature sensor. My first thought was that it is thermal conductive paste, but that is supposed to remain flexible like putty. It could also be a high temperature glue that attaches the temperature sensor to the underside of the ceramic plate. The temperature sensor is attached to a rubber boot that pushes it against the ceramic plate. Anyhow, the paste was not doing its job of adhering to the temperature sensor and ceramic plate which probably changed the calibration required for the sensor to measure the temperature. The paste drying and crumbling away could be the cause of the unit frequently shutting off when I use my large iron skillet. The weight of the skillet might alter the thermal contact the sensor makes with the ceramic plate. Under the theory that the paste surrounding the temperature sensor insulates it, I removed the paste to make it report a lower temperature. So far the cooktop has not shut off while cooking with the large skillet. With the cooktop less sensitive to high temperature, I must be careful not to overheat it.

    jsv1heqF1U1j8.jpg
    http://i.minus.com/dsv1heqF1U1j8/COOKTOP1.JPG

    As can be seen in the close-up photo in the lower right corner of the circuit board, the wires for line and neutral are connected opposite to how they are marked on the circuit board. The black wire is supposed to be line, attached to the small pin on the plug and to the fuse. The white wire is neutral and attached to the wider pin on the polarized plug. Reversing them does not affect the operation of the cooktop but is sloppy. After taking the photos, I fixed it.

    j5c2QEUHKZjpG.jpg
    http://i.minus.com/d5c2QEUHKZjpG/COOKTOP2.JPG

    The wire in the induction coil is mostly spaced and laminated, but in a few spots adjacent loops appear to touch except for the laminate insulating them. The outer loop of wire on the left and lower side of the coil is poorly spaced.

    The brushless fan should be good for longevity.

    Overall the cooktop looks reasonably well built and is accessable for repair. Not having surface mount parts also eases repair.

    To minimize the problem about the cooktop shutting off when the AC power is over 10% of nominal (132 VAC RMS or 13.2 VDC at my batteries), I lowered the float voltage of my charge controller to 13.2 VDC. Because my batteries normally reach float mode before 9 am and I use the cooktop after 10 am, this should help. I will try this for 6 months while monitoring the effect on the state of charge of my batteries.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    One problem with any temperature measurement is that you want to know the temperature of the pan, not the ceramic under it. And if the pan bottom is not flat the induction still works well but the temp sensor will be off. An electric skillet can mount the thermostat in good thermal contact with the bottom of the cooking surface. :)

    Unless the pan makes good thermal contact with it, the ceramic will not be heated at all in an induction burner.
    SMA SB 3000, old BP panels.
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Re: Sunpentown Mr. Induction SR-964T Induction Cooktop

    The bottom surface of my medium skillet is concave and the large one is convex making it touch the center of the ceramic plate just above the temperature sensor. That could be the explanation.
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