Just finishing the Porsche 924 conversion. I have an Alltrax 7245 and an isolated 84 volt system. The Albright contactor has a 12V coil operating on the vehicle system so I am able to pull it without energizing the 84V system. This I did while the last battery cable was disconnected. I then flashed the cable against the post and was rewarded with an impressive white flash. My question is am I charging the controller capacitors or have I done something stupid in the wiring and how can I tell the difference? I do not have a precharge resistor in the line (yet). Please be gentle with your criticism as I am very sensitive.
tommyt
Do I have a problem?
Hi Tom
As you suspect, you will get a flash when you first complete the circuit to the controller, even if you have wired everything correctly. This is just the capacitors filling up. The precharge resistor is needed to prevent this arcing at the contactor terminals, by limiting the initial current.
The Alltrax should run OK off 24V, so for your first test I would suggest just connecting two batteries. The LED on the end of the Alltrax should flash green once (if I remember correctly) when the controller is powered up.
Let us know how it goes!
As you suspect, you will get a flash when you first complete the circuit to the controller, even if you have wired everything correctly. This is just the capacitors filling up. The precharge resistor is needed to prevent this arcing at the contactor terminals, by limiting the initial current.
The Alltrax should run OK off 24V, so for your first test I would suggest just connecting two batteries. The LED on the end of the Alltrax should flash green once (if I remember correctly) when the controller is powered up.
Let us know how it goes!
-
Tom Thomson
- Posts: 64
- Joined: Fri Aug 31, 2007 12:48 am
problem?
Malcolm
You were right. To prove it, I put a 250 ohm resistor in the battery loop, was rewarded with a small flash then (after getting myself emotionally prepared) jumped over the resistor with a piece of 18 ga and vwah-lah no sparkys. I feel so much better.
tommyt
You were right. To prove it, I put a 250 ohm resistor in the battery loop, was rewarded with a small flash then (after getting myself emotionally prepared) jumped over the resistor with a piece of 18 ga and vwah-lah no sparkys. I feel so much better.
tommyt
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