Question.... How can I start a 1HP (240v) sealed unit refrigeration motor with an 1800 Inverter . It will run if I start with the gen set.. then switch it across to the inverter. But won't start with using the inverter,,Is there a compassitor or some easy start method I can use.. so I don't have to use the 240v gen set.
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Refrigeration motor
Good day John, The refrigerator motor seems to be working ok, by your statement. Items to look at are D.C. Amps into the inverter. When the refrigerator starts the current flow is high and as the motor gets up to speed the current flow drops off. It appears to me that the inverter may be too small to supply the current for the refrigerator motor. Using Ohms law, it looks like the Refrigerator motor is using about 4 amps to run. just as a rull of thumb look at the D.C. current into the inverter, I would think the current would be twice the output current or higher. This would allow for surge voltage at the start cycle of the refrigerator motor. Inverters draw a lot of D.C. to provide A.C. output. I hope that this helps. Good sailing AL Check with an electrican to verify.
Good day John, The refrigerator motor seems to be working ok, by your statement. Items to look at are D.C. Amps into the inverter. When the refrigerator starts the current flow is high and as the motor gets up to speed the current flow drops off. It appears to me that the inverter may be too small to supply the current for the refrigerator motor. Using Ohms law, it looks like the Refrigerator motor is using about 4 amps to run. just as a rull of thumb look at the D.C. current into the inverter, I would think the current would be twice the output current or higher. This would allow for surge voltage at the start cycle of the refrigerator motor. Inverters draw a lot of D.C. to provide A.C. output. I hope that this helps. Good sailing AL Check with an electrican to verify.
Try a Kick Start unit
Try a Hard start capacitor made for low voltage starting compressor motors. These units cost about $25. Be sure the one you buy is rated for the HP and voltage range. There are only two wires to connect and is simple to install takes only five minutes.
Try a Hard start capacitor made for low voltage starting compressor motors. These units cost about $25. Be sure the one you buy is rated for the HP and voltage range. There are only two wires to connect and is simple to install takes only five minutes.
Starting a 1HP motor in reply
Thank you for your reply to my question Al and Richard..You are right it uses just over 4amps I will look into the capacitor and check out all your information.. Will let you know my results Many thanks. John
Thank you for your reply to my question Al and Richard..You are right it uses just over 4amps I will look into the capacitor and check out all your information.. Will let you know my results Many thanks. John
OK,
Stop everybody. Am I missing something? He said he trying to start a 240 volt motor. Last time I looked, that requires two inverters. One for each positive lead into the motor. P.S. John, being from Australia, is your wiring the same as ours? I have no idea. In North America AC (alternating current) is 110-120 volts, 60 cycles. Two such supply wires drive 220 volt devices.
Stop everybody. Am I missing something? He said he trying to start a 240 volt motor. Last time I looked, that requires two inverters. One for each positive lead into the motor. P.S. John, being from Australia, is your wiring the same as ours? I have no idea. In North America AC (alternating current) is 110-120 volts, 60 cycles. Two such supply wires drive 220 volt devices.
Starting 1HP motor. 2nd reply.
Fred thanks for your interest, In Australia we have 240AC 1 red wire which ranges between 220 - 240v 1 black wire which is the negative and our cycle is 50hz. 1 green which is the earth... But on the inverter we only use 1 red 1 black wire.. the red supplying 240v out of the inverter. The problem being that the inverter isn't big enough to handle the start up of the 1HP motor Once it is running it only uses 4 amps. and inverter handles it OK. I would like to start it without having to start the Gen set.Suggestion was to find a suitable capacitor, At present trying to find where to get the right size capacitor or someone that knows about them here. Still looking John Thanks
Fred thanks for your interest, In Australia we have 240AC 1 red wire which ranges between 220 - 240v 1 black wire which is the negative and our cycle is 50hz. 1 green which is the earth... But on the inverter we only use 1 red 1 black wire.. the red supplying 240v out of the inverter. The problem being that the inverter isn't big enough to handle the start up of the 1HP motor Once it is running it only uses 4 amps. and inverter handles it OK. I would like to start it without having to start the Gen set.Suggestion was to find a suitable capacitor, At present trying to find where to get the right size capacitor or someone that knows about them here. Still looking John Thanks
John, Gotcha.
One rule for start capacitors, (Freds rule) you can't get one that's too big. For that matter you can't install too many. I have three on my home heatpump so it starts on the generator. You know, back over a hundred years ago when standards were being worked out for electricity in this country, there was a huge power struggle (oops, sorry) between the competing sellers. 120 volt 60 cycles won of course. Thomas Edison's company wanted to sell DC. He would have needed a power plant every three miles. That was the idea. Henry Ford was his friend. These guys were industrialist. Anyway, many people here (even this board) consider 120vac as lethal. Maybe, if you have a nearly dead heart. I don't know anyone who hasn't done the '60hz shuffle' and they are all still doing pretty good. But your power standards and the levels used in Europe are simply deadly. Do you folks lose a significant number of citizens to those power levels? Scary.
One rule for start capacitors, (Freds rule) you can't get one that's too big. For that matter you can't install too many. I have three on my home heatpump so it starts on the generator. You know, back over a hundred years ago when standards were being worked out for electricity in this country, there was a huge power struggle (oops, sorry) between the competing sellers. 120 volt 60 cycles won of course. Thomas Edison's company wanted to sell DC. He would have needed a power plant every three miles. That was the idea. Henry Ford was his friend. These guys were industrialist. Anyway, many people here (even this board) consider 120vac as lethal. Maybe, if you have a nearly dead heart. I don't know anyone who hasn't done the '60hz shuffle' and they are all still doing pretty good. But your power standards and the levels used in Europe are simply deadly. Do you folks lose a significant number of citizens to those power levels? Scary.
inverter input voltage
Good day John, Looking at the voltage and amps out, I believe that you will need about 75 amps of DC to run your refrigerator. when you start the motor it will draw about 10% to 20% more. You may need to think of about 100amps of DC to run that inverter to get the power out that you need. Good winds, AL
Good day John, Looking at the voltage and amps out, I believe that you will need about 75 amps of DC to run your refrigerator. when you start the motor it will draw about 10% to 20% more. You may need to think of about 100amps of DC to run that inverter to get the power out that you need. Good winds, AL
Starting a 1HP Motor Reply no 3
G'day Al, Thanks for your reply. I had time this week to check the frige motor. turned all AC DC off , started the frige on 240v, it used 6.25 on AC multimeter and ran on 3.5 to 4 amps. We have 2 motors 55 amp hr alternators running at 1500 revs, switched it across to the inverter, the inverter monitor reading was 13.1v and 47 amps DC. the AC wattage was aprox 500w. Switched one motor off, and ran one motor at 1000rev and it maintained the amps and voltage. Have to check out another supplier this week to find the right capacitor. Still checking. May go sailing this week.. John Thanks
G'day Al, Thanks for your reply. I had time this week to check the frige motor. turned all AC DC off , started the frige on 240v, it used 6.25 on AC multimeter and ran on 3.5 to 4 amps. We have 2 motors 55 amp hr alternators running at 1500 revs, switched it across to the inverter, the inverter monitor reading was 13.1v and 47 amps DC. the AC wattage was aprox 500w. Switched one motor off, and ran one motor at 1000rev and it maintained the amps and voltage. Have to check out another supplier this week to find the right capacitor. Still checking. May go sailing this week.. John Thanks
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