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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Diagnose Inverter motor dirve - aircon unit
Hi all,
I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. I am a low level electronics experience chap, so need some advice on how these caps would typically be charged. They are used, as i understand it, to smooth the supply to the variable speed fan and compressor in the aircon unit. Looking at the other test points on main pcb, everything else checks out ok. Here is a link to the (large) manual for the aircon unit if any one fancies helping me out. http://www.manualslib.com/download/8...Ash-18aie.html Id apreciate any help/guidance, Many thanks, Steve |
#2
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Diagnose Inverter motor dirve - aircon unit
On 23/07/2016 3:18 PM, Mr Sandman wrote:
Hi all, I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. I am a low level electronics experience chap, so need some advice on how these caps would typically be charged. They are used, as i understand it, to smooth the supply to the variable speed fan and compressor in the aircon unit. Looking at the other test points on main pcb, everything else checks out ok. Here is a link to the (large) manual for the aircon unit if any one fancies helping me out. http://www.manualslib.com/download/8...Ash-18aie.html Id apreciate any help/guidance, Many thanks, Steve You have worked through the logic of the trouble shooting guide for the charge failure ?? |
#3
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Diagnose Inverter motor dirve - aircon unit
Mr Sandman wrote:
I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. ** Gobbledgook. Large electros acquire *DC voltage* after being charged. What sort of multimeter / voltmeter are you using ?? An old moving coil one by any chance - many of the latter read double voltage on the AC ranges compared to the DC ranges if mistakenly used for DC. Reverse the probes and the reading drops to zero. .... Phil |
#4
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Diagnose Inverter motor dirve - aircon unit
"Rheilly Phoull" wrote in message ... On 23/07/2016 3:18 PM, Mr Sandman wrote: Hi all, I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. I am a low level electronics experience chap, so need some advice on how these caps would typically be charged. They are used, as i understand it, to smooth the supply to the variable speed fan and compressor in the aircon unit. Looking at the other test points on main pcb, everything else checks out ok. Here is a link to the (large) manual for the aircon unit if any one fancies helping me out. http://www.manualslib.com/download/8...Ash-18aie.html Id apreciate any help/guidance, Many thanks, Steve You have worked through the logic of the trouble shooting guide for the charge failure ?? yes i have, i went through the tests for main board, the only test that was wrong was test three, giving readings i mentioned. There is no further troubleshooting that would identify the component that is faulty as i could see in the manual. cheers steve |
#5
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Diagnose Inverter motor dirve - aircon unit
"Phil Allison" wrote in message ... Mr Sandman wrote: I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. ** Gobbledgook. Large electros acquire *DC voltage* after being charged. What sort of multimeter / voltmeter are you using ?? An old moving coil one by any chance - many of the latter read double voltage on the AC ranges compared to the DC ranges if mistakenly used for DC. Reverse the probes and the reading drops to zero. --------- I am using a digital multimeter, a fairly decent one. Probing the caps directly i get the voltages i mentioned. is this showing ripple indication a bad capacitor rather than a bad charging component? the caps show no signs of leakage or expansion externally. thanks for the help, sorry im a newbie, and dyslexic so may sound muddled. cheers steve |
#6
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Diagnose Inverter motor dirve - aircon unit
On 23/07/2016 10:18 PM, Mr Sandman wrote:
"Rheilly Phoull" wrote in message ... On 23/07/2016 3:18 PM, Mr Sandman wrote: Hi all, I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. I am a low level electronics experience chap, so need some advice on how these caps would typically be charged. They are used, as i understand it, to smooth the supply to the variable speed fan and compressor in the aircon unit. Looking at the other test points on main pcb, everything else checks out ok. Here is a link to the (large) manual for the aircon unit if any one fancies helping me out. http://www.manualslib.com/download/8...Ash-18aie.html Id apreciate any help/guidance, Many thanks, Steve You have worked through the logic of the trouble shooting guide for the charge failure ?? yes i have, i went through the tests for main board, the only test that was wrong was test three, giving readings i mentioned. There is no further troubleshooting that would identify the component that is faulty as i could see in the manual. cheers steve So as Phil says, you should be checking for DC at the caps and if that is only 43vdc then the fault is in the charging board. Are you intending to repair the board or replace it? |
#7
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Diagnose Inverter motor dirve - aircon unit
Mr Sandman wrote:
Mr Sandman wrote: I have an aircon unit that failed. Fault code 'PU' says the capacitor charging circuit failed, this is confirmed by checking the voltage at the three large electrolytic caps which show 43vdc, but oddly 85v ac. The expected voltage at the capacitors should be 180-380vac. ** Gobbledgook. Large electros acquire *DC voltage* after being charged. What sort of multimeter / voltmeter are you using ?? An old moving coil one by any chance - many of the latter read double voltage on the AC ranges compared to the DC ranges if mistakenly used for DC. Reverse the probes and the reading drops to zero. --------- I am using a digital multimeter, a fairly decent one. ** Make and model - please ! Probing the caps directly i get the voltages i mentioned. ** What about when you reverse the leads? FYI: There has got to be at least one DMM maker who uses a half wave rectifier directly coupled to the DC meter circuit - mimicking how an moving coil multi-meter does the same job. .... Phil |
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