Paralleling Power Supply Units Made Easy ???
I am considering paralleling a couple of 20a variable adjustable psu's for 40a charging. According to what I have read on the world wide inter-web, it can be done quite easily, provided the following ...
Forum Discussion
MEX posted:
http://www.acopian.com/redundant-power-supplies.html
REPLY:
My 1620 (0-16v 0-20a) has :
Load Regulation (0-100%): less than or equal to 50mV ;
Transient Response Time (50-100% Rated Load): less than or equal to 1ms ;
Line Regulation is only listed for 230v as (198-264Vac) less than or equal to 10mV.
The blurb on their website states:
Intelligent protection: Output short circuit protection, Tracking Over Voltage Protection (OVP), Tracking Over Current Protection (OCP), Over Temperature Protection (OTP)
??? Is this what the article refers to when it says:
Power supplies don’t always go low when they fail; the voltage can instead go high – by 50% or more in some cases – and fry the load. Therefore, it’s vitally important that power supplies used in redundant applications should always be equipped with fast-acting overvoltage protection to assure that the output voltage can’t go much higher than the nominal.
??? As for the term redundancy, it seems to be a big issue if the load is some important system, ie; equipment involved in say medical, or communications? Is it that big a deal when simply charging 12v batts with two psu’s?
Quote: “In summary, be sure to use a supply that can put out a voltage high enough to compensate both the diode and wiring drops under worst-case conditions (usually, low line and maximum load current), and also has the desired load voltage within its adjustment range.”
??? As I’ve learned, V.D. (not the nasty one) decreases as current decreases (thanks BFL). I have seen this while charging, and by the time amps are relatively low (say 10amps), the v.d. is also very low… like .02 -.01v. EDIT: If using two psu’s in parallel to BOOST/ABS CHARGE a 215Ah bank, at 40 amps and .08 maximum v.d., is there little cause for concern? (or is .08 volts out of 16, at maximum load current, a lot? ) ...these are the numbers I'm currently getting when charging with a pm4b-45.
So, I'm essentially asking if I have achieved reasonably low v.d. with my wiring and such, and therefore low resistance overall. And I guess I'm assuming that by reducing overall v.d./R there would be less potential variation in output voltages from the two psu's. In other words, lower overall R leads to lower discrepancies. And at what point would voltage discrepancies play a major role in my given situation? a 10th of a volt, a 100th, a 1000th?
Thanks!
http://www.acopian.com/redundant-power-supplies.html
REPLY:
My 1620 (0-16v 0-20a) has :
Load Regulation (0-100%): less than or equal to 50mV ;
Transient Response Time (50-100% Rated Load): less than or equal to 1ms ;
Line Regulation is only listed for 230v as (198-264Vac) less than or equal to 10mV.
The blurb on their website states:
Intelligent protection: Output short circuit protection, Tracking Over Voltage Protection (OVP), Tracking Over Current Protection (OCP), Over Temperature Protection (OTP)
??? Is this what the article refers to when it says:
Power supplies don’t always go low when they fail; the voltage can instead go high – by 50% or more in some cases – and fry the load. Therefore, it’s vitally important that power supplies used in redundant applications should always be equipped with fast-acting overvoltage protection to assure that the output voltage can’t go much higher than the nominal.
??? As for the term redundancy, it seems to be a big issue if the load is some important system, ie; equipment involved in say medical, or communications? Is it that big a deal when simply charging 12v batts with two psu’s?
Quote: “In summary, be sure to use a supply that can put out a voltage high enough to compensate both the diode and wiring drops under worst-case conditions (usually, low line and maximum load current), and also has the desired load voltage within its adjustment range.”
??? As I’ve learned, V.D. (not the nasty one) decreases as current decreases (thanks BFL). I have seen this while charging, and by the time amps are relatively low (say 10amps), the v.d. is also very low… like .02 -.01v. EDIT: If using two psu’s in parallel to BOOST/ABS CHARGE a 215Ah bank, at 40 amps and .08 maximum v.d., is there little cause for concern? (or is .08 volts out of 16, at maximum load current, a lot? ) ...these are the numbers I'm currently getting when charging with a pm4b-45.
So, I'm essentially asking if I have achieved reasonably low v.d. with my wiring and such, and therefore low resistance overall. And I guess I'm assuming that by reducing overall v.d./R there would be less potential variation in output voltages from the two psu's. In other words, lower overall R leads to lower discrepancies. And at what point would voltage discrepancies play a major role in my given situation? a 10th of a volt, a 100th, a 1000th?
Thanks!
