I need help of an REE.

[brian_po]

meron lang bumabagabag sa aking isipan 

scenario:
a compressor supposed to run in 220VAC. And the supplied voltage is only 180VAC.
our service technician reccommend to install a AVR but the customer refuse due to financial reason.

while im exploring to uncle google. 1 post from elab and other post from different forum got my attention.
sir RPDzycho said that he also experience this problem on his ACU. and the remedy was he installed a capacitor.

in all ACU and Refrigeration products, all of this have a capacitor used in starting. but im wondering
where they did  put the another capacitor.?

and what is the proper formula in computing this..
as i've understand during college days. if we oversize the capacitor to its original specs. the result would be burnt windings.

"sir rpd pa help naman, sa modification mo na ginawa s ACU mo. i need some formula regarding this matter."
nabasa ko din kasi sa ibang forum na tested na ito.

basic wiring ng ACU


basic wiring ng ref


nabasa ko kasi na pwede patakbuhin ang compressor sa 180V kahit 220V ang rated.
tapos may nilagay "daw" na capacitor  .. ayoko kasi maniwala sa daw 
gusto ko may basis.. 

pa edit naman ng diagram kung san nilalagay ang extra capacitor and the formula in computing this
thanks

[brian_po]

up

[ahlburuto]

Question:

Bakit 180vac ang naging supply voltage mo? Anung naging cause? Mababang rating ba ng transformer sa lugar nyo? Or voltage drop due to long cable runs?


Yung isang capacitor na nilalagay eh ang tawag dun running capacitor. Mababa lang rating nun. Parang power factor correction din. Nakaparallel yun sa L1 at L2 ng motor.... Ang computation nun eh dapat alam mo ang PF ng motor mo...

BR

[piona]

Yong running/starting Capacitors ay built-in talaga yon sa mga Capacitor Start Motors para umikot ito during start-up.

Yon namang Capacitor to Boost a Line Power ay para makorek yong Power Factor ng Line Source, tawag dito ay VAR (Volt-Ampere-Reactive Power) Capacitors. Ang kadalasang gamit nito pag nag-deteriorate na ang Power Factor ng Line Source dahil sa mga Inductive Loads nilalagyan nila ng VAR Capacitors para makorek ito at mag-unity uli ang PF ng Line Source.

Tawag lang nila dito VAR Capacitor pero actually isang ordinary Capacitor lang talaga ito para bumalanse sa Inductor na Loads.

Tama si sir Tanochie, kailangan talagang malaman ang Line Power Factor with the Inductor Loads para ma-compute kung anong value ng Capacitor ang ilalagay across sa Line Source para maging unity uli ang PF ng Line.

It could really boost the voltage and power of the line source kung ang PF talaga nito ay mababa. 

Ito link sa Wiki with formulas how to compute the value of the Capacitor to be use : http://en.wikipedia.org/wiki/Volt-amperes_reactive

[robbietan]

you should complain about your "low voltage" situation to the utility that serves your area. you have that right under the magna carta for residential users.

[kinyo]

adding a capacitor across the AC lines will not magically correct your undervoltage condition ... power factor correction is useful only for long transmission lines where the line inductive impedance is causing the voltage drop ... PFC will not fix undervoltage problem in a residential setup

[brian_po]

thanks s mga replies..

iniisip ko lng kung pwede gumana.. sa 180VAC kc may nabasa ako na pwede kaso wlng formula na binigay!
oo nga pwede mag reklamo s meralco pero worst case scenario lng naman kung tlgang pipilitin.  

thanks s VAR capacitor idea..
check ko ito  

edited: may nakalimutan

opo meron talaga na capacitor sa compressor.. ginagamit para s starting. naka paraller sa running and starting windings kung s A/C
ang question ko lng is yung may idadagdag pa na capacitor to start the motor on low voltage scenario

thanks sa VAR idea.. reviewhin ko muna ito

[piona]

Yon pong value ng starting capacitor ay tama lang na mag-hi impedance ito kapag nakapagstart na ang motor, computed ito siguro at +/-10% ng supply voltage.

[Roland]

kunting comments ko lang, di po ako magaling sa mga theory, base lang sakin sa experience ko as hvac tech sa mideast.(saudi and dubai)
para sakin hindi logical or advisable ang paglagay ng ano mang capacitor para paganahin ung compressor sa ganun ka babang voltahe. kung maglolow voltage sa line cgurado tataas ang amperahe ng compresor mo(in ratio). kaya big chance titigok compressor mo. kaya nga pagnaglowvoltage bigla ang isang lugar cgurado madaming a/c at ref ang masusunogan ng compressor.
The best na paraan is pataasin ang boltahe sa area nyo or gumamit ka ng avr or step up transformer.

I love this site ang dami kong natutnan dito specially sa electronics. gusto ko kase na matuto pa sa electronics.

[brian_po]

pa help naman sa computation...
180VAC given..
ano value ng capacitor needed..

[piona]

pa help naman sa computation...
180VAC given..
ano value ng capacitor needed..

Kailangan lang yong Angle Displacement ng voltage at current bro, with all the loads connected sa linya. Ang usually gamit dito ay phase angle meter o di kaya multifunction na wattmeter.

VAR = V x I x Sine of the Angle Displacement.

Also: Power Factor = Cos sa Angle Displacement ng V at I.

Apply mo na ang post mong formula above para makuha mo ang C.

[piona]

Pag-multifunction power meter nga pala ang gamit mo bro, ididisplay na niya lahat pF, var, watt, i , v , etc etc.....so apply mo nalang yong formula mo para makuha ang C.

[piona]

Ito sample ng wattmeter (posted by Robbietan), may measurement na ng Power Factor.

[brian_po]

^
wala ako instrument eh 
sorry ah late reply.. medyo busy last week

[fherdzpowerhaus]

meron lang bumabagabag sa aking isipan 

scenario:
a compressor supposed to run in 220VAC. And the supplied voltage is only 180VAC.
our service technician reccommend to install a AVR but the customer refuse due to financial reason.

while im exploring to uncle google. 1 post from elab and other post from different forum got my attention.
sir RPDzycho said that he also experience this problem on his ACU. and the remedy was he installed a capacitor.

in all ACU and Refrigeration products, all of this have a capacitor used in starting. but im wondering
where they did  put the another capacitor.?

and what is the proper formula in computing this..
as i've understand during college days. if we oversize the capacitor to its original specs. the result would be burnt windings.

"sir rpd pa help naman, sa modification mo na ginawa s ACU mo. i need some formula regarding this matter."
nabasa ko din kasi sa ibang forum na tested na ito.

basic wiring ng ACU


basic wiring ng ref


nabasa ko kasi na pwede patakbuhin ang compressor sa 180V kahit 220V ang rated.
tapos may nilagay "daw" na capacitor  .. ayoko kasi maniwala sa daw 
gusto ko may basis.. 

pa edit naman ng diagram kung san nilalagay ang extra capacitor and the formula in computing this
thanks

bakit hindi yata nila masagot?.. nalito na kayo sa wiring diagram..

[dan.enriquez]

^ madugo ang tanong ni sir BRIAN pero pano nga ba?

[fherdzpowerhaus]

ang starting capacitor is during starting of high torque motor load dahil sa mataas ang starting current nito,ang running capacitor is additional phase for three phase motor using a single phase supply voltage, depende sa wiring diagram, capacitor is storage of voltage to use in the circuit,..yun ang pagkakaalam ko but sa theory and formula kayo na ang bahalang mag-analyst kung tama ba or mali ang nabanggit ko.

your suggestion is highly appreciated...


+639295792763
fherdzpowerhaus

[brian_po]

^medyo magulo na hind eh..
parang ibig sabihin m sir na if you would add a capacitor parallel to line it would create another phase.. "yes!! syempre" 
but it can be used only on jerking the motor or for testing purposes only and cannot be use in normal operation...
in case that your compressor is designed to work in 3phase supply..

in my case.. my compressor is designed to run in a single phase supply..
but common to all compressors there is a running and starting winding.. that's why meron starting capacitor na nakalagay..

sa scenario na post ko ay.. the rated voltage of the compressor is 220VAC. so it will run un 240V - 200VAC..
unfortunately, the voltage supply in the area is 180VAC only... don't ask me why.. why it is not 200-200VAC.. i'm not an employee of the service provider.. i dunno if what is the name of the power company in mindanao...

worse comes to worse..
the customer is blaming our product.. even if there is no problem in our product obviously..
but as a technical person and our service tech also asking for technical support. we need to do something just to pacify our clients.
that's why i'm looking for some formulas kay uncle google or kay wikipedia...

Last remedy would be.. blame it to the power company.. 

[achievers]

saan mkabili ng power factor meter at magkano. achiever

[DigitalMind]

ganyan din sa cebu. i complaint about the swinging power voltages. knowing na medyo industrial yung katabi namin (sharing a single phase transformer).

thus no choice but go to 3 phase and rent a transformer...