Inverter problem on PV system

[John Dunkley]

I would be grateful for some advice on an inverter problem on my PV system.

Background info:

Brand new 300 watt continuous true sine wave inverter that has a 1000 watt
output surge capacity.
12 volts DC to 240 volts AC

With my PC and LCD monitor connected to the inverter, the inverter shuts
down some 15 seconds after the PC boot-up.
I have data logging equipment and logging the current drawn by the PC/LCD
the maximum current drawn is 0.7 amps which equates to approximately 170
watts. There is of course a lot of PC hard disk 'activity' during these
first 15 seconds.

If I remove the LCD monitor, the PC boots up OK and after waiting 2-3
minutes until the PC boot up activity finishes, and then connect the LCD
monitor to the inverter, the system runs OK with no shut down of the
inverter. The LCD monitor by itself draws a fairly constant 30 watts. Power
drawn is then a fairly stable 80 watts with the occasional jump to 170 watts
with hard disk activity.

The only thing I can think of is that there are some higher 'surges'
produced by the PC during those first 15 seconds that my data logger is not
capturing that is shutting the inverter down - but 170 watts is still a
long way from the inverters 1000 watt surge capacity.

Assistance/advice regarding this problem would be appreciated.

I might add that I am a newbie to this particular news group and it is very
nice to see the manners and assistance provided by its participants. This is
very refreshing compared to some other news groups I monitor!

Must be all gentlemen here!

JD
Australia.

 

[Rheilly Phoull]

I would be grateful for some advice on an inverter problem on my PV
system.
Background info:

Brand new 300 watt continuous true sine wave inverter that has a 1000
watt output surge capacity.
12 volts DC to 240 volts AC

With my PC and LCD monitor connected to the inverter, the inverter
shuts down some 15 seconds after the PC boot-up.
I have data logging equipment and logging the current drawn by the
PC/LCD the maximum current drawn is 0.7 amps which equates to
approximately 170 watts. There is of course a lot of PC hard disk
'activity' during these first 15 seconds.

If I remove the LCD monitor, the PC boots up OK and after waiting 2-3
minutes until the PC boot up activity finishes, and then connect the
LCD monitor to the inverter, the system runs OK with no shut down of
the inverter. The LCD monitor by itself draws a fairly constant 30
watts. Power drawn is then a fairly stable 80 watts with the
occasional jump to 170 watts with hard disk activity.

The only thing I can think of is that there are some higher 'surges'
produced by the PC during those first 15 seconds that my data logger
is not capturing that is shutting the inverter down - but 170 watts
is still a long way from the inverters 1000 watt surge capacity.

Assistance/advice regarding this problem would be appreciated.

I might add that I am a newbie to this particular news group and it
is very nice to see the manners and assistance provided by its
participants. This is very refreshing compared to some other news
groups I monitor!
Must be all gentlemen here!

JD
Australia.

Take a reading at the inverter input terminals and see if thats where it's
"Sagging". Probably one at the output too if thats OK.

 

[John Dunkley]

Two 12 volt 100 AH each in parallel, 100% SOC, deep cycle DELKO Calcium,
brand new.

JD

 

[John Dunkley]

Rheilly,

Are you suggest voltage or current readings at inverter input - or both?

Readings supplied are for current at output of inverter, but I can do a
voltage reading at output as well.

Thanks for your reply.
JD

----- Original Message -----
From: "Rheilly Phoull" <[email protected]>
Newsgroups: alt.solar.photovoltaic
Sent: Friday, April 14, 2006 6:58 PM
Subject: Re: Inverter problem on PV system

 

[sam]

If I remove the LCD monitor, the PC boots up OK and after waiting 2-3
minutes until the PC boot up activity finishes, and then connect the LCD
monitor to the inverter, the system runs OK with no shut down of the
inverter. The LCD monitor by itself draws a fairly constant 30 watts. Power
drawn is then a fairly stable 80 watts with the occasional jump to 170 watts
with hard disk activity.

A few tests that might shed some light:

Boot up the system as described then try a disk scan, or something that causes continious disk
activity to see if the inverter can cope.

Is the 12v wiring from the battery to the inverter able to handle the 170W without a significant
voltage drop?

Is the inverter working properly? Can it handle 2 or 3 100W light bulbs?

Try another device with a switch mode power supply with similiar power requirements. A reasonable
sized TV perhaps.

Cheers,
Sam

 

[John Dunkley]

Don't say things like that - makes me nervous! - made in Taiwan - isn't
everything these days?.

Have been in electronics for 42 years, opened it up, and this is a quality
built product. Has unconditional warranty in writing for 4 years.

Was not cheap to purchase - AUD$300.

Will carry out some other tests suggested by NG replies and report back.

JD

 

[John Dunkley]

Hi Sam,

Will carry out these suggested tests and report back to NG

Can report however that cabling from inverter to battery is original as
supplied, 1 metre long and very heavy duty cable.

Regards,
JD

 

[George Ghio]

Old imac (crt) will not start and run on my 300W inverter

New imac (flat panel) does just fine.

Doubt very much 1000W surge.

You have already pinpointed the problem i.e.;

 

[John Dunkley]

Thanks to all for interest in my problem.

Here is an update:

Input to inverter is 12.55 volts DC when operating
Output voltage from inverter when operating is 242 volts AC

With LCD monitor running off mains i.e. not off inverter, and just the PC
running off the inverter, the inverter shuts down with high level of hard
disk activity, scan disk, disk clean up etc.

Seems like my PC is pulling a lot more than the measured 240 volts @ 0.7 amp
= 170 watts output when things are really happening inside the PC!

Inverter runs 250 watt incandescent lamps with no problems at all!

Maybe a UPS between the inverter and the PC may be an answer??

I too don't believe the claimed 1000 watt surge rating.

Thanks guys but I am now running out of ideas.

John Dunkley
Australia
VK5JE

 

[John Dunkley]

True, but it might protect my solar powered inverter from spikes from my PC
system?

JD