Abnormal DC Reading While On Shore Power

[JohnK]

New to the Escape with a 2020 E21C coming off of 10 years of Casita ownership, I just now induced a problem which I can't solve.

In equipment left to me by the previous owner I found the 110 v plug pictured below. Silly me, thinking it may be some sort of night light I plugged it into the exterior ac outlet to check and immediately tripped the GFCI. So I pulled the plug out, reset the GFCI and checked voltage. The EMS read 122 VAC / 60 HZ shore power, and E-0 all of which as I understand is nominal. However my digital RV voltmeter now reads only 13.19 VDC at the DC outlets whereas it used to read 13.65 VDC which I also understand is nominal for the WFCO 8955PEC. Both 40 amp DC fuses are good and the 30 amp converter circuit breaker is not tripped. I did manually trip and reset that 30 amp CB but that resulted in no DC voltage change at the DC outlet. Still 13.19 vdc.

Are there any other CBs or fuses elsewhere that I should be checking or am I missing something else? I hope this hasn't fried a portion of the WFCO. If it has I guess I'll be replacing it earlier than I thought with a PD4645VL. I didn't want to be modifying this trailer this early.

John

[John in Santa Cruz]

that looks to be a neutral bonding plug, it connects the AC "neutral" to the 'Ground', and is meant for use with unbonded generators, you plug it into one outlet on the generator, while you power your trailer or other load off another outlet on the generator. the generator *should* be grounded via an external wire when you do this

it easily could trip a GFCI, but that shouldn't impact anything with the DC converter. 13.2V is what you might see from a DC converter when the batteries are fairly deeply discharged, OR as a maintenance voltage once the batteries are 100% fully charged.

[JohnK]

Thanks for the reply John and for informing me what that plug is. These batteries (two 6 volt) are fully charged. Yes I'm aware that 13.2 volts is a storage level for fully charged batteries, but that comes with multi-stage smart chargers which the WFCO 8955PEC charger is not. It charges at a straight 13. 6 volts.

[TTMartin]

Originally Posted by JohnK

New to the Escape with a 2020 E21C coming off of 10 years of Casita ownership, I just now induced a problem which I can't solve.

In equipment left to me by the previous owner I found the 110 v plug pictured below. Silly me, thinking it may be some sort of night light I plugged it into the exterior ac outlet to check and immediately tripped the GFCI. So I pulled the plug out, reset the GFCI and checked voltage. The EMS read 122 VAC / 60 HZ shore power, and E-0 all of which as I understand is nominal.

As mentioned that is neutral grounding plug to be used with a generator so the EMS doesn't detect an open safety ground fault and prevent power from reaching the trailer. Rather than bypassing the other safety features of the EMS to use the generator, it allow use of the EMS and generator together protecting your trailer from damage due to high or low generator voltages, or power surging on and off as the generator runs out of fuel.

Originally Posted by JohnK

However my digital RV voltmeter now reads only 13.19 VDC at the DC outlets whereas it used to read 13.65 VDC which I also understand is nominal for the WFCO 8955PEC. Both 40 amp DC fuses are good and the 30 amp converter circuit breaker is not tripped. I did manually trip and reset that 30 amp CB but that resulted in no DC voltage change at the DC outlet. Still 13.19 vdc.

Are there any other CBs or fuses elsewhere that I should be checking or am I missing something else? I hope this hasn't fried a portion of the WFCO. If it has I guess I'll be replacing it earlier than I thought with a PD4645VL. I didn't want to be modifying this trailer this early.

Sounds like TMI.

IMO, you're measuring things to a meaningless precision.

FWIW, the WFCO converter is a multi stage charger. Each stage will have a different voltage.

1. NORMAL MODE (Absorption) powers all DC loads, and keeps the battery charged.

2. TRICKLE MODE (Float) is initiated when there is no significant change in current draw for 44 continuous hours, keeping the battery charged while prolonging its life.

3. FAST CHARGE MODE (Bulk) kicks in to charge the battery if it’s significantly discharged due to improper maintenance, long term storage, or significantly heavy system overloads. Bulk mode is maintained for 4 hours (max.) to prevent possible battery damage.

[TTMartin]

Originally Posted by JohnK

Thanks for the reply John and for informing me what that plug is. These batteries (two 6 volt) are fully charged. Yes I'm aware that 13.2 volts is a storage level for fully charged batteries, but that comes with multi-stage smart chargers which the WFCO 8955PEC charger is not. It charges at a straight 13. 6 volts.

POWER CENTERS: WF-8955

WF-8955

The WF-8900 Series has revolutionized RV power centers with its lighter weight, decorative doors and superior features. The WF-8955 model provides 55 Amps and a clean, constant 13.6 VDC nominal output, for reliable operation of electronics and appliances.

Automatic three-stage charging extends the life of your battery with output voltage modes of 13.2 VDC range “float” mode, 13.6 VDC range “absorption” mode, and a 14.4 VDC range “bulk” charge mode. The 8900 Series also maintains peace and quiet, as the cooling fan runs only when needed.

[JohnK]

Thank you TTMartin for your reply. Upon purchasing the trailer I researched the converter on the OEM's website and found this statement: "The WF-8955 model provides 55 Amps and a clean, constant 13.6 VDC nominal output, for reliable operation of electronics and appliances." This led me to believe it is a single stage charger.

This morning upon reading your reply I went back to the website and found the more complete description which includes your multi-stage charging description. This is making me feel better.

I have had the trailer in storage plugged in to shore power for several days running a fan to accelerate interior outgassing, but with the battery turned on only when I am present which is only an hour or two a day. While the battery was nearly topped off entering storage, it has not been turned on for an entire 44 consecutive hours but AC power has been applied for several days enabling the WFCO to sense "no significant current draw for 44 or more consecutive hours" even though it was not charging the battery the entire time. So apparently I am experiencing normal operation of this multi-stage charging system which I originally thought was a single stage system.

Thank you for setting me straight.

John