Diesel heater (error code 7) When invertor turned on

b0re

Member
Joined
Aug 31, 2018
Messages
48
Hello,

I have a Diesel heater powered by an Orion 24v-12v DC-DC Converters Non-isolated. When turned on everything works fine as soon as I turn on the invertor the Diesel heater shows error code 7, this means low voltage to the controller. I checked the controller's voltage when on and the voltage is 14v and the output of the Orion 24v-12v DC-DC Converter is 14v with no voltage drop.

Could the Orion Non-isolated part be causing an issue?

Thanks
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
573
My guess is that the inverter momentarily draws a lot of current when first switched on, enough to briefly lower the voltage before the DC/DC converter can compensate.

You could try adding a "pre-charge circuit" to the inverter switch to reduce the current it can initially draw.
eg. https://k9-build.blogspot.com/2018/07/spark-fire-of-resistance-or-how-not-to.html

Another possible option would be to add a capacitor to help keep the voltage more stable.

It might also be a cable thickness/length issue.
 

Redpacket

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Feb 28, 2018
Messages
1,263
Like ajw22 suggested, try a large capacitor, eg 2,200uF 25V across the controller input but also add a diode eg 1A/100V like this:
Orion 12V positive output > diode > controller with capacitor.
This way, when the inverter pulls a brief surge, the cap is not drained by the inverter & holds the controller input up.
 

b0re

Member
Joined
Aug 31, 2018
Messages
48
I will swap the wire and if that does not work I will then try the capacitor option

Thanks
 

b0re

Member
Joined
Aug 31, 2018
Messages
48
Did a test today I added an additional cable to the 12v still had the same problem. This time i turn the 12v off, then turned the inverter on then turn the 12v on im still getting the same problem.

Could this be related to the Orion 24v-12v DC-DC Converters Non-isolated. I can buy an isolated one do you think this would help?
 

OffGridInTheCity

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Dec 15, 2018
Messages
1,462
Don't want to run you in useless circles or ask dumb questions (more than usual :) ) - but has it been verified that the heater works when connected directly to a 12v Lead Acid battery? In other words, are you sure its the 24DC -> 12DC is where its failing?
 

b0re

Member
Joined
Aug 31, 2018
Messages
48
Its 12v. Yes, I have been using it for 6months had no issues.
 

floydR

Active member
Joined
Aug 23, 2017
Messages
996
Have you tried a precharge circuit like ajw22 suggested? This may be a silly idea but 24 inverter--->to 12volt battery charger to 12v LiFePO4/lead acid battery to Diesel heater. Wouldn't need to be a large 12v charger. How many watts does the Diesel heater use?
Could it be that the control on the Diesel heater has gone bad?

Later floyd
 
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