-
Momentary Voltage Drop
I had the following issue happen last night and haven’t been able to determine what caused it. I’ll run it by everyone in hopes that someone knows what caused it.
We arrived at Pacific Shores in Newport, Oregon yesterday afternoon and hookrd up the utilities. Checked the Techlink screen which showed 122V on each leg. A while later I heard a “click click” coming from the electrical cabinet in the bedroom closet. It was difficult to pin point exactly where the click click was coming from but appeared to be coming from the back wall behind a long terminal board. There was no relay that I could find near the click click sound. Then I noticed the interior lights would momentarily dim each time I heard the click click sound.
I hooked my Fluke to eack side of the 12V house buss bar in the bedroom electrical cabinet. It was reading around14.6V. Each time I heard the click click, the voltage would drop to around 13.6 and then return to around 14.6V. I then metered several 120V outlets throughout the coach. The voltage read around 121V until the click click where it would drop to 119V.
I thought maybe the shore power was causing the issue so I shut off the shore power at the coach shore power breaker in the bay. The click click continued without shore power being connected. After about an hour with my head stuck in the electrical cabinet, I still could not locate the source of the click click and the resulting drop in all voltages. I gave up and intended to call Marathon in the morning.
The click click sounded all night until about 6:30 this morning and then abruptly stopped. I checked both DC and AC voltages. DCV was a constant 13.6 and the AC was a constant 119Vs. The Techlink screens still show 122ACV on both legs.
It has me baffeled, I sure would like to know what caused this to happen…..
-
4 Replies
-
This is a long shot Chris, but there is a noticable click each time the 120v hot water heater button is pressed that actuates a relay inside the cabinet behind my AC breaker box in the bedroom. Did you have the 120v hot water heater on? Maybe there was something going on with the relay or the hot water heaters.
-
Hi Tom, The water heaters had not been turned on as we usually don’t turn them on until we run out of the hot water already heated by the engine.
BTY, I forgot to mention that it was about 10 seconds between each time I heard the click click. Kept us awake.
-
This is a guess solely based on information you provided.
The 14 volt DC reading and the 13 volt reading are what I would expect to see when the DC system is being charged at absorb or bulk, and the lower of the two immediately after shutting off charging current.
Is there a relay or self restoring circuit breaker associated with the charging circuit on the inverters?
Several things make that guess completely wrong however because the voltages should be expected to be the reverse of one another with high DC voltage and low AC voltage showing the inverters are charging, and the reverse when they are not. The second reason the above guess is wrong is if the batteries are in the front of the bus, then inverters are going to be nearby.
Is there a connection between the chassis batteries and the house batteries that has some relay between them?
-
There is a relay for the house/chassis jump, but it’s in the small bay curb side just ahead of the engine access door and you can’t hear it inside.
Log in to reply.