CBE PC100

[jimbo07g41]

Good morning. I have just joined but been a long time reader of the forum.

 

I have a La Strada Trento with a CBE PC100 kit fitted. Been a great van over the last 6 years of ownership. I have had a strange fault were my leisure battery died and my vehicle battery died. I replaced both batteries roundabout lockdown 1 and noted that I still had the following issues.

 

1. Leisure battery not charging when vehicle running.

2. Control panel always shows the starter battery as low. It is at 12.5 and starting the vehicle ok.

3. Starter battery wont charge on the hook up.

4. Dometic fridge appears to light on gas but does not cool.

5. After a recent trip the van stereo (linked direct to leisure battery) started flashing. Battery found to be at 11.5.

 

I have read that there can be issues with the distribution unit or is this likely to be the CBE van charger? Any pointers would be grateful.

[Alanb]

Hi,

 

Welcome to the forum.

 

Have you checked the fuse and the connection to the starter battery (B1)?

 

A blown fuse or bad connection on the B1 supply could account for all problems listed.

 

Does your fridge cool on 240V when on EHU? (The fridge will require a maintained control 12V supply in order for it to function. Possibly it is managing to ignite, then the habitation (B2) battery voltage is collapsing?

 

Please note that the heart of the CBE system is the 12V distribution board, e.g. DS300xx or DS520xx.

 

In relation to the reading for the starter battery voltage, please note that my CBE system displays a reading with the starter battery disconnected.

 

Has the vehicle been jump started? This can blow CBE battery fuses in some instances.

 

 

Alan

 

 

[jimbo07g41]

Hi Alan,

 

very interesting. I will check the fuse in my lunch break. I had issues with the alarm system running the starter battery down and I wonder whether they jump started it when it was in the garage.

 

Will come back with an update.

 

[jimbo07g41]

So both fuses appear to be intact. However, there looks like some weird stains on the an electrical square thing in the middle. Might the PCB be damaged?

 

[rayc]

jimbo07g41 - 2021-04-21 2:13 PM

 

So both fuses appear to be intact. However, there looks like some weird stains on the an electrical square thing in the middle. Might the PCB be damaged?

 

 

I think that is the mains battery charger??

What voltage do you get on the battery inputs of the DC unit, see page 14 of the link. Check the voltages on 21 & 22 with meter negative on 20

https://www.12voltplanet.co.uk/user/downloads/CBE%20PC100%20KIT%20&%20PC200%20KIT%20instruction%20manual.pdf

[mikefitz]

There should be a 50 amp fuse near the positive terminal of the engine battery and the leisure battery. I suspect the engine battery fuse has failed. Although technically the fuse should be near the battery positive post its possible it could have been installed anywhere between the battery and DS control unit. I think your van is based of the Ford chassis, there is often a fused feed from the starter battery at the seat base ( either drivers or passenger) so the 50A fuse for the CBE system may be near by.

 

Other issues could be failure of the combining relay in the DS300 or the lack of a 'key on' igition live feed to the DS3000

 

Mike

[jimbo07g41]

rayc - 2021-04-21 2:19 PM

 

jimbo07g41 - 2021-04-21 2:13 PM

 

So both fuses appear to be intact. However, there looks like some weird stains on the an electrical square thing in the middle. Might the PCB be damaged?

I think that is the mains battery charger??

What voltage do you get on the battery inputs of the DC unit, see page 14 of the link. Check the voltages on 21 & 22 with meter negative on 20

https://www.12voltplanet.co.uk/user/downloads/CBE%20PC100%20KIT%20&%20PC200%20KIT%20instruction%20manual.pdf

Yes it is the mains charger! Ops school boy error. All fuses are ok on the distribution unit. I will have to get the multi meter out and the cover off the distribution unit.

[jimbo07g41]

mikefitz - 2021-04-21 5:01 PM

 

There should be a 50 amp fuse near the positive terminal of the engine battery and the leisure battery. I suspect the engine battery fuse has failed. Although technically the fuse should be near the battery positive post its possible it could have been installed anywhere between the battery and DS control unit. I think your van is based of the Ford chassis, there is often a fused feed from the starter battery at the seat base ( either drivers or passenger) so the 50A fuse for the CBE system may be near by.

 

Other issues could be failure of the combining relay in the DS300 or the lack of a 'key on' igition live feed to the DS3000

 

Mike

Yes mk7 transit. Looks like the feed might go onto the fuse box under the bonnet. There are two 50 amo fuses next next to the leisure battery.

[Alanb]

jimbo,

 

As an alternative to separately mounted fuses for B1 and B2 (starter and habitation batteries), your motorhome could be fitted with "Boite Relais Securite".

 

To check which applies in your case locate the 12V distribution board CBE DS300xx where the 12V habitation fuses are fitted. On carefully removing the cover the board will be fitted with 2 or 3 M6 terminal studs B1, B2, & -ve or B2-ve.

 

If the B1 terminal is missing, then you probably have two "Boite Relais Securite" fitted. These are about 3" square, containing a relay and two fuses. They will be connected via two large and two small wires. For more details see this thread, scroll down for photos etc. When fitted one of the boxes is connected to the starter battery (B1), and serves as the split charge relay. The starter battery fuse for the CBE system will be the bolted in (2 x M5 studs) red 50A Midi fuse in that box.

 

Otherwise you are looking for separate fuses as suggested above by mikefitz.

 

Alan

 

PS I have just seen that while I have been typing, you have posted regarding the fuses. That's life.

[jimbo07g41]

Looks like I have the standard b1 and b2 posts. Thanks for all the help, I am learning lots about the system. I will get the multi meter out when I can to perform some tests.

[Derek Uzzell]

Your photo indicates that your CBE ‘Distribution Box’ is a DS-300.

 

There are 3 photos of a generic DS-300 unit on this link

 

https://www.camperflash.it/en/home/electricity/centraline-ed-accessori/cbe-panel-for-user-distribution-ds300-caravan-camper.2.1.4023.gp.54092.uw

 

with the central image showing the printed-circuit board.

 

There is a caveat with CBE systems in that they may have an element of ‘bespoke tailoring’ where CBE has provided the motorhome manufacturer with a Distribution Box and control-panel to meet the manufacturer’s specifiic requirements.

 

For example, my 2005 Hobby motorhome had waste-water tank heaters as standard and operation of those heaters was controlled via the control-panel and DS-300 unit. So, if either the Hobby’s control-panel or DS unit had become problematical, a generic panel or DS box would not have been a suitable replacement.

 

If your La Strada Trento has a ‘bespoke’ CBE system, you may be able to confirm this by checking the label on the lid of the DS Box to see if it just carries “DS-300”, or there’s a suffix ("DS-300 LS” perhaps) to indicate that it’s a La Strada ‘special’.

[jimbo07g41]

Yes, I have gone through the manual that came with the van and it has LS at the end. DS300-LS.

 

It appears to have a heater on top of the waste tank under the van and the control panel lay out is slightly different. It has a separate button for the fridge ignition, one for water pump and then the power button.

[jimbo07g41]

Derek Uzzell - 2021-04-22 8:42 AM

 

Your photo indicates that your CBE ‘Distribution Box’ is a DS-300.

 

There are 3 photos of a generic DS-300 unit on this link

 

https://www.camperflash.it/en/home/electricity/centraline-ed-accessori/cbe-panel-for-user-distribution-ds300-caravan-camper.2.1.4023.gp.54092.uw

 

with the central image showing the printed-circuit board.

 

There is a caveat with CBE systems in that they may have an element of ‘bespoke tailoring’ where CBE has provided the motorhome manufacturer with a Distribution Box and control-panel to meet the manufacturer’s specifiic requirements.

 

For example, my 2005 Hobby motorhome had waste-water tank heaters as standard and operation of those heaters was controlled via the control-panel and DS-300 unit. So, if either the Hobby’s control-panel or DS unit had become problematical, a generic panel or DS box would not have been a suitable replacement.

 

If your La Strada Trento has a ‘bespoke’ CBE system, you may be able to confirm this by checking the label on the lid of the DS Box to see if it just carries “DS-300”, or there’s a suffix ("DS-300 LS” perhaps) to indicate that it’s a La Strada ‘special’.

Looks identical to mine. Maybe they have just labeled them up differently as the layout is the same and they are only simple on/off switches on my van. There is also instructions on how to setup the jumper switches.

[Derek Uzzell]

The Instructions Manual for a ‘generic’ CBE PC100/PC-200/DS-300 system can be viewed here

 

https://www.libble.eu/cbe-pc-100/online-manual-824523/

 

Besides being a different shape to the standard control-panel shown on Page 11, my 2005 Hobby’s panel (image attached below) used Button 13 to operate the waste-water tank heaters and there was no button for an awning light.

 

The fact that your DS-300 Distribution Box has a “LS” (La Strada) suffix indicates that it is not ‘standard’ (eg. the provision of a fridge ignitioin button is unusual) and (presumably) if you needed a new DS-300 and fitted the standard one, some functionality would be lost.

[jimbo07g41]

Hi just an update.

 

I get 13.3 on post b2 and 23.4 on post b1.

 

I cant find the 50 amp fuses for the life of me. I have found the hidden ford transit fuses behind the battery and all are ok.

 

There is a separate RCD box but no fuses.

[jimbo07g41]

Just to add with the engine running both B1 and B2 are at 13.4 volts. The starter battery shows as fully charged with the engine running. Am I being a dimwit has it always disconnected from the starter battery when the engine is not running?

 

The charge light is on the panel so the engine alternator is joining up with the leisure side. I am starting to suspect the fridge as everything else is now working. The only fault I have found is a slightly loose positive terminal on the leisure battery.

[Derek Uzzell]

jimbo07g41 - 2021-04-24 4:41 PM

 

...I get 13.3 on post b2 and 23.4 on post b1...

 

What does that actually mean?

 

CBE’s PC-100 document refers to the “car" battery (ie. the starter battery) as B1 and the “services” battery (ie. the leisure battery) as B2. If you were following rayc’s earlier advice and checking voltages at the DS-300 Distribution Box (presumably with your motorhome’s battery-charger operating) a 13.3V charge MIGHT be OK, but surely 23.4V cannot be correct?

 

I came across a Southdowns Motorhome Centre advert for a 2009 La Strada Trento

 

http://www.southdownsmotorcaravans.co.uk/stock/2791/pixindex.html

 

and, amongst the photos is one of the PC-100 control-panel showing the fridge button you mentioned earlier (and arrowed in red on the image attached below). This is definitely not a generic PC-100 panel and the variation from standard will almost certainly be reflected within the DS-300 Box.

[jimbo07g41]

So with the hook up on it is 14.4 on b2 and 13.12 on b1.

 

I have no idea why I get 24 with the hook up switched off.

 

Nice to see another Trento. Mine is a top of the range model with the more powerful engine and a few extras. Remi blinds and a bike carrier.

[Keithl]

Jimbo,

 

Do you have a solar panel?

 

If yes then the 23.4 volts may be the output of the solar panel/regulator without a battery connected. ie the battery it is meant to be connected is not connected (eg has a blown fuse).

 

Keith.

[jimbo07g41]

No Solar panel. I have no idea why I get 24v. However as soon as the engine is running or on the hook up it goes down to normal 13v. charging.

 

 

[Alanb]

jimbo07g41 - 2021-04-24 6:36 PM

 

Just to add with the engine running both B1 and B2 are at 13.4 volts. The starter battery shows as fully charged with the engine running. Am I being a dimwit has it always disconnected from the starter battery when the engine is not running?

 

The charge light is on the panel so the engine alternator is joining up with the leisure side. I am starting to suspect the fridge as everything else is now working. The only fault I have found is a slightly loose positive terminal on the leisure battery.

I still suspect a blown fuse, or faulty connection between the starter battery positive, and the B1 terminal of the CBE DS300. This was also the opinion of mikefitz, as posted above.

 

Like Derek, I cannot understand the reading of 23.4V on B1. This reading must be false, due to the typical high sensitivity of the multimeter. If the 12V starter battery was actually connected to this terminal, I would expect a reading of no more than about 14.4V

 

With the ignition on the CBE system receives an ignition (switched) +ve from the vehicle. This supply is monitored electronically on the DS300 board and connected via a relay when about 13.2V is exceeded. The supply connected by the relay is "simulated D+", and is used to operate the split charge and fridge relays.

 

The split charge relay contact connects between B1+ and B2+ on the PCB. With the engine running the voltages at the CBE B1+ and B2+ terminals will be almost identical. I say almost because if B2 is being charged, and the fridge is running on 12V, there will be a small voltage drop across the split charge relay. Particularly because CBE choose to supply the fridge from the B2 side of the split charge relay. In these conditions the B1+ terminal will have a slightly higher voltage than the B2+ terminal.

 

It is my understanding that the charge light, or battery coupled indicator only indicates that the simulated D+ is live. It does not detect, or indicate actual charging.

 

"So with the hook up on it is 14.4 on b2 and 13.12 on b1."

 

CBE systems in common with Schaudt provide a trickle charge to B1 (starter battery). This is achieved by using an additional low current output from the CB 516 or similar charger, the "S" signal. This signal activates the mains ON indication on the display and operates a small relay (12mm cube) at the lower RH corner of the PCB above the terminals. The adjacent thermistor (blue disc) limits the current to about 2A max, and the diode (black cylinder) prevents current flowing from the starter battery via this path.

 

From experience, I would expect B1 to be about 0.6V less than B2, but not the 1.28V suggested by the readings given.

 

I assume that the Varta battery in the photograph is B2 (habitation/service). From much past experience with rented Transit PVCs in NZ, this was under the LH or passenger seat, while the starter battery (B1) was under the drivers seat. If this is the case, a photo of the battery under the RH seat may be helpfull.

 

To help move forward, may I suggest this further test.

 

With engine running, measure voltage directly across the starter battery, and also on the DS300 between B1+ve and B2? -ve. If the circuit from the starter battery is intact, they should be similar.

 

To divert from the 12V problem, I am concerned that there does not appear to be an RCD fitted to the vehicle. The mains distribution box to the RHS of the DS300 only seems to contain a two pole MCB. There is no yellow RCD test button visible. The equivalent CBE installation in my PVC has a two pole RCD with a two pole 13A RCD adjacent. Total 4 x 18mm modules width.

 

In the interests of safety, I trust that you have replaced the covers on the charger, and mains unit.

 

Alan

[Derek Uzzell]

jimbo07g41 - 2021-04-24 7:29 PM

 

So with the hook up on it is 14.4 on b2 and 13.12 on b1...

A photo in one of your earlier postings indicates that the battery charger is probably a CBE CB516 unit

 

https://www.12voltplanet.co.uk/user/downloads/CBE%20Switch%20Mode%20Battery%20Charger%20instruction%20manual.pdf

 

This should deliver (to the leisure-battery) about 14.3V on the charger’s gel setting or 14.1V on its 'wet-acid' setting. I’d expect a Trento to start life with a gel leisure-battery, but another photo of yours shows a Varta battery that I’m guessing is no-maintenance wet-acid type. So you may want to check whether the charger’s battery-type selection switch is set to PB (wet-acid) or gel.

 

Are you sure the ‘snowflake’ button I’ve arrowed in red on the control-panel image relates to the fridge? On a generic PC-100 panel that button is used to switch on an awning-light that turns off automatically when the vehicle’s motor is started. On my Hobby’s PC-100 panel that button switched on two 12V heaters fitted low down through the side of the external waste-water tank. As those heaters were quite high amperage, they would only operate when the Hobby’s leisure battery was being charged by the motorhome’s alternator or by its onboard CB516 charger when the motorhome was connected to a 230V power supply - so if your Trento has a waste-water tank heater, I could well believe it would have a similar PC-100 panel button arrangement to my Hobby’s.

 

Dometic 3-way fridges are normally (invariably?) turned on or off via their own integrated controls and will operate independently of a motorhome’s control-panel and irrespective of how the control-panel’s switches might be set. I can’t see the need for a supplementary ‘fridge’ switch on a control-panel, particullarly as this would introduce an obvious risk of the fridge being switched off if the panel were inadvertently turned off.

 

(Regarding there being no RCD, evidently this ‘omission’ is (or was) commonplace with German-built motorhomes. It was highlighted in this 2009 forum discussion.)

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/arto-rcd-device/17911/

[Brian Kirby]

Alanb - 2021-04-24 10:56 PM

 

jimbo07g41 - 2021-04-24 6:36 PM

 

Just to add with the engine running both B1 and B2 are at 13.4 volts. The starter battery shows as fully charged with the engine running. Am I being a dimwit has it always disconnected from the starter battery when the engine is not running?

 

The charge light is on the panel so the engine alternator is joining up with the leisure side. I am starting to suspect the fridge as everything else is now working. The only fault I have found is a slightly loose positive terminal on the leisure battery.

.................................

 

Like Derek, I cannot understand the reading of 23.4V on B1. This reading must be false, due to the typical high sensitivity of the multimeter. ........................................................

Alan

Wild cards!! :-D

 

If we believe the multi-meter, that 23.4V reading suggests that something is connecting the two batteries in series rather than in parallel. Might there be a relay somewhere that has either failed to switch, or welded itself closed where it should have opened, to leave the two batteries connected in series?

 

Could this possibly relate to the "bridge" link on the DS300 board intended for use with an AES fridge, which leaves the fridge heating element permanently "on" when the engine is turned off? (I believe some variants of the CBE equipment also use this bridge for compressor fridges.)

 

Ours (3 way Dometic fridge: not AES) was delivered with the bridge connected and caused a bit of puzzlement when I noticed it was still drawing current with the engine stopped. The CB 516 charger supplied the load when on hook up, so the fridge continued to work normally. I forget what alerted me to the problem, but when the van went in for its first damp check I mentioned the fridge running off 12V when it shouldn't. Shortly enter electrician with a big grin, saying he'd found and removed the bridge on the DS300 and all was now working correctly! I had the impression it wasn't the first he'd found! I'd never understood the bridge functionality for AES fridges, but just assumed that if Knaus supplied the van with the bridge present, it would be for good reason. Can't rely on anything, can you? 8-)

[Keithl]

Is there any possibility the leisure battery and/or control panel could have lost their ground connection?

 

This may allow the two batteries to appear in series under certain conditions and also could explain the low voltage reading of the starter battery if in reality the panel was not grounded?

 

Just thinking out loud and throwing a curved ball in...

 

Keith.

[Alanb]

Keithl - 2021-04-25 9:35 AM

 

Is there any possibility the leisure battery and/or control panel could have lost their ground connection?

 

This may allow the two batteries to appear in series under certain conditions and also could explain the low voltage reading of the starter battery if in reality the panel was not grounded?

 

Just thinking out loud and throwing a curved ball in...

 

Keith.

 

I like this curved ball. The habitation electrics of a motorhome generally use a wired rather than an earth (chassis) return. The earth or chassis connection is only necessary as a return path for items supplied from the base vehicle system, which include alternator charging of the habitation (service) battery, fridge 12V power, and D+ or simulated D+. It should be quite possible for the habitation system, with the exclusion of the fridge 12V, to function on mains charger only. However as the simulated D+ appears to be functioning, that raises a problem. Perhaps a relatively high resistance earth (chassis) connection???

 

Alan