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Home > Inverter Support > Pure Sine Wave Inverter Support > Pure Sine Wave (ISW) Inverters: No AC Output
Pure Sine Wave (ISW) Inverters: No AC Output
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How to troubleshoot No AC Output


Check DC Voltage
Check DC voltage on the back of the inverter.  It must be between 10.5 and 16 volts in order for the inverter to operate correctly. (Use Multi-meter)


Disconnect all loads
This action will remove the installation as a possible cause of the problem. 

Disconnect the battery from the inverter
Disconnect the battery, wait a half hour, and then reconnect, this will reboot the inverter’s processor and clear any possible error states.


Reconnect Battery and Boot Unit
Turn the inverter on with no load attached.  Check for any error LED’s which may occur.  Measure the output voltage of the inverter.  Note you will only obtain a true reading with a true RMS meter.

Re-apply AC Loads
If this works, bring the loads on-line, one by one.  Check inverter after applying each load.

Check battery Voltage
If the voltage stays within the DC voltage range of the inverter.  This eliminates the possibility that an ineffective circuit from the battery is causing the issue. If the voltage is erratic, solve that problem by tracing the cause of the erratic voltage and fixing it, and then get back to the inverter. 

Power save mode
Some perceived problems actually arise from features in the inverter like idle mode, or power save. Such features, when enabled, allow the inverter to turn off when the load is low, but can create the very real perception of a problem.  Different inverters have different means of enabling these features.  It may be easiest to check the manual to determine if your inverter has these features and how they are enabled and disabled.

Check GFCI
If the inverter has a GFCI check to see if it is tripped.  Hit the reset button if it has.


Measure AC Out Instructions 

Measure the AC output on the GFCI on the front of the unit.  Make sure the green light is on the GFCI and measure ac output with a multimeter.


- Battery terminals are loose.  
- Battery cable is not sized correctly
- Battery terminals are corroded or rusty.  
- Battery is weak. 
- Battery is discharged.  
- Battery is faulty.  
- Battery terminals are reversed.  Connect terminals correctly. 
- Battery is not properly charged.  
- Battery has lost electrolyte. 

Products covered in this article: GP-ISW-200, GP-ISW-400, GP-ISW-700, GP-ISW-1000, GP-ISW-1500, GP-ISW-2000, GP-ISW-3000, GP-ISW-4000

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