ESPAR high amp draw on start

[Shack]

Looking for anyone who has experienced high amp draw on start-up (enough to trip a 15A breaker.)

I have a D5 Airtronic that is on its second season of pretty smooth operation. The other day it kicked off the breaker. Each successive re-start keeps tripping the CB. However, it appears to be getting farther through the start cycle with each re-attempt. I've stopped re-starting as I don't want keep pushing my luck. (I need to respect the breaker's purpose, and I don't want to building up excess fuel in the unit.)

Symptoms:
-No fault codes. These are deleted when the breaker trips.
-Combusition air intake is free and clear.
-Fans turning freely, and 20A fuses are all intact.
-Good system voltage 13.3vdc measured at the pigtail, pins 1 & 10. (System requirement is 11-14 vdc).
-Last attempt, fuel pump was ticking away slowly (normally) then the breaker tripped right when it usually doubles speed for the start-up.
-Was running well for three weeks on diesel, (was on kersene all last year).

Are there any tech savvy folks out there willing to take a stab at this puzzle?

Cheers!

[DeepFrz]

Are you sure you have the right size fuse. The installation manual says the main fuse should be 25 amp.

[Dsanduril]

Hate to say it, but I suspect the real question may be "why did it operate on a 15A breaker?". At startup the major load will be the glow plug/igniter and Eberspacher lists the startup load at "< 250W" which works out to around 20A at your voltages. The glow plug comes on with the low fan setting for 45 seconds before the rest of the system, and stays on for a total of 165 seconds.

The fan starts up in the fan stage "LOW". The glow plug starts with a 3 second delay. After approx. 45 seconds the fuel supply starts and the fuel / air mixture in the combustion chamber ignites. The fan switches from fan stage "LOW" to fan stage "MEDIUM". The glow plug is switched off after 165 seconds, when a stable flame has formed. The fan switches from fan stage "MEDIUM" to fan stage "HIGH".

From what you describe it sounds like things are kicking off when the extra load is put on (LOW = 15W or ~1A, MED = 30W or ~2.5A, up to 85W = ~7A at BOOST). Given that Eberspacher says "<250" and lists normal operation maximum at 15-85W, I'd hazard a guess that the glow plug is around 165W to 220W (depending on when the glow plug cuts out, certainly not at low fan) = ~11A to 17A and you managed last year to just skirt by at 15A, and this year not so much (maybe just slightly lower voltages?). I'd say double check the fuse rating (should be 25A as DeepFreeze notes per the manual), then change the breaker to a 20A.

[CarlF]

The trip delay on a breaker could well give you 165 seconds at a moderate overload with the glow plug --- see Blue Sea chart for 15 amp breaker below. The breaker may simply be a bit out of tolerance after a winter of heavy load.

I'd replace the breaker (might as well put in the correct size too)

[CarlF]

duplicate

[goboatingnow]

Diesel will cause longer start times and higher currents

Dave

[witzgall]

Wesasto specifies that the heater is wired directly to the batteries, with an inline fuse. Check to see if Espar specifies the same?


Sent from my RM-917_nam_usa_100 using Tapatalk

[mub]

I checked on mine... as it is just been troublesome this year.
My meter on peak hold says 18A on startup - it is a D5L which is a lot older.
The interesting thing I found was that mine is wired to the start battery not the house battery.
If this is similar then the 15A breaker will defiantly be stressed.

[Shack]

Sorry for the late response, but the holidays kept me from digging into boat work!! I had to give thanks to everyone’s input on this one. Definitely enough advice provided to move the ball forward a few yards! Thanks again!

FIRST! I all of you an apology for mis-reading the break rating. I do have a 20A breaker! But it is being tripped. I finally obtained a clamp-on ammeter to watch the start-up sequence, and the breaker tripped almost instantaneously with only a couple amps (and prior to fuel delivery). I then jumped the breaker by hot leading it to a bus bar. The start sequence went up to 23A. I gave it several seconds at 23A before, I chicken out and a killed the start (my system has two 20A inline fuses that I was concerned about blowing them).

CarlF - That trip delay diagram is very helpful to understand the breaker tolerance for peak amps. I was looking unsuccessfully for something like that, and I think it explains why my 20A breaker has not tripped until now.

I am going with a bad breaker as one of possible causes, but it may not be the root cause. I need to check with an ESPAR tech to double check my start-up loads. Since the system has two 20A inline fuses, I’m inclined to believe that 23A draw on start-up may be above normal and symptomatic of something else like a fouled glow plug.

DeepFrz – Thanks for the 25A recommendation. My ESPAR installation guide shows only a direct connection to battery (and no breaker).

Dsanduril – Roger, all. Thanks for the additional specs especially the 250W start load!

On electric heat for now!
Thanks Again and Happy New Year!

[senormechanico]

Try unplugging the fan motor and check the draw.
Possibly a shorted winding / seized or sticking bearing.
Just a thought.