Morningstar tristar pwm 45 amp plus 2 pcs 300 watts pv

[ongbunsing]

Good Day this the first time I posted a thread. I need advise if my morningstar tristar pwm 45 amp could handle 4 pcs of 300 watts pv 24 volts

My current setup morning tristar 45 amp pwm 2 pcs 300 watts pv with 2pcs 100ah deep cycle and 1500watts pure sine wave inverter 24 volts

questions:
1. can my controller handle 4 pcs 300 watts
the pv specs
peak power 300 watts
voltage (vmp) 54.7 v
current (imp) 5.49 a
open circuit voltage (Voc) 64.0v
short circuit current (isc) 5.87 a

2. why when i check pv voltage without controller it is 54 volts when I connect it to controller it became 25.4

3. can I series the wirring connection to increase the voltage can my controller handle it?

Thank for the support

[ckhorne]

questions:
1. can my controller handle 4 pcs 300 watts

Have you tried Morningstar's string calculator? http://www.morningstarcorp.com/en/strings/calc.php

2. why when i check pv voltage without controller it is 54 volts when I connect it to controller it became 25.4

You're comparing open circuit voltage vs load voltage. In an open circuit, basically the electricity has no where to "flow", so you see much different results than if you have a load to complete the circuit.

3. can I series the wirring connection to increase the voltage can my controller handle it?

Try the string calculator with your panels' specific parameters.

[Sunking]

G
questions:
1. can my controller handle 4 pcs 300 watts
the pv specs
peak power 300 watts
voltage (vmp) 54.7 v
current (imp) 5.49 a
open circuit voltage (Voc) 64.0v
short circuit current (isc) 5.87 a

2. why when i check pv voltage without controller it is 54 volts when I connect it to controller it became 25.4

3. can I series the wirring connection to increase the voltage can my controller handle it?

Thank for the support

Well I got some good news, and I got some really bad news for you. You are going to learn the pitfall of PWM controllers the hard way, and you will not like it one little bit.

A1. Is the good news. Your controller can more than handle 1200 watts input assuming you configure the panels all in parallel. This will give a total of 4 x 5.49 amp = 21.96 amps of just call it 22 amps. You can double your panel wattage if using the exact same panels in parallel.

A2 I assume you have 24 volt batteries right? That would be perfectly normal and any PWM controller when operating at 100% duty cycle or full ON will match the battery voltage + about 1 volt. Now here is your lesson and you will not like it one little bit. All PWM Controllers Input Current = Output Current. You maximum possible input current = 22 amps, and thus your maximum output current = 22 amps. At max current input your max output to the batteries is 24 volts x 22 amps = 528 watts. Do you see a problem? You have 1200 watt panels and only get 528 watts. Cool huh?

A3. You sure can. Wire them 2 x 2 and you get a input/output current of 11 amps. 24 volts x 11 amps = 264 watts out of a 1200 watt panel.

There is only 1 solution to your problem. Get rid of your controller and get a 60 amp MPPT controller. Wire your panels in either series or parallel and you will get an output of 24 volts x 47.5 amps or 1140 watts. Told you would not like it.

[ongbunsing]

ouch!

Thanks ckhorne and sunking for the quick support. I will wire my panel in series for the mean time I will get a new controller this December mppt one.

I have one thing in mind can I stack two controller one pwm and one mppt going to a common battery bank or use to different brand of controller and stack them in a common battery bank. thanks again

[Sunking]

I will wire my panel in series for the mean time

That would be foolish you did not read my reply Wire them all in series and you get 5.5 amps x 24 volts = 132 watts out of 1200 watts in panels. Be my guest wire them up in series.

[ongbunsing]

thanks

Thanks sunking i did wired it parallel. Last thing how many panel of this kind would my controller handle I have 5 pcs of this I am afraid my controller can't handle it

[Sunking]

Thanks sunking i did wired it parallel. Last thing how many panel of this kind would my controller handle I have 5 pcs of this I am afraid my controller can't handle it

I already answered this.

A1. Is the good news. Your controller can more than handle 1200 watts input assuming you configure the panels all in parallel. This will give a total of 4 x 5.49 amp = 21.96 amps of just call it 22 amps. You can double your panel wattage if using the exact same panels in parallel.

[ongbunsing]

thanks

Thanks again sunking for the help