Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 06-03-2019, 14:48   #1
Registered User
 
Ortolan's Avatar

Join Date: Apr 2010
Location: Where it's warm!
Boat: PDQ MV34 Powercat
Posts: 66
Regulating Voltage to a Fridge

I have a Nova Kool fridge/freezer combo unit with a single Danfoss compressor which I have made many improvements to (include heavier wiring). It now works much better BUT it REALLY likes 12.8+ volts. By early AM, when voltage drops to 12.3, the fridge coldplate begins to defrost even though the compressor is running continuously. As soon as I start charging the battery, it immediately begins to frost up & cycle normally.

I am now thinking - is there a voltage regulator device which would output around 12.8 volts even when my battery drops to 12.3? (I realize the draw would increase).

If it would also reduce higher voltages to around 12.8, that would be an advantage when equalizing my batteries at a high voltage.

Russ
__________________

Ortolan is offline   Reply With Quote
Old 06-03-2019, 15:56   #2
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 7,810
Re: Regulating Voltage to a Fridge

Russ, I had the same conditions with my A/B Cold Machine for years. I beefed up the wiring. I replaced the condenser fan.


Turned out it was the electronic module. I found that out after I left the boat for a month while I moved from SF to Canada (all systems off of course). The fridge was dead. I followed Richard Kollmann's advice and traced it down to the module.


It's been working fine since 2016.


https://c34.org/bbs/index.php/topic,9065.0.html


Good luck.
__________________

__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is online now   Reply With Quote
Old 06-03-2019, 16:04   #3
Registered User

Join Date: Jan 2017
Posts: 11,838
Re: Regulating Voltage to a Fridge

Yes there are lots, look for 13.8V output, usual standard for radio / nav gear.

Voltage regulator, DC converter, DC charger "12V to 12V". Don't over-buy ampacity, as you go high current gets lots more expensive.

But there will be losses, so be sure it's not just an Ah capacity issue, or bank deteriorating with age.

LFP chemistry is much better than lead that way.
john61ct is online now   Reply With Quote
Old 06-03-2019, 16:13   #4
Registered User

Join Date: Jan 2017
Posts: 11,838
Re: Regulating Voltage to a Fridge

Victron Energy Orion 12/12-30A (360W) Isolated DC-DC converter

Great example of pricey overkill, isolated output, but may be too low V for you.

Check out MasterVolt, Osculati, BEP / Marinco?


At the other extreme, no brand but likely OK, cheap enough to carry spares.

https://www.amazon.com/gp/aw/d/B077QJK59C

Branded but only rated 5A
https://www.amazon.com/gp/aw/d/B017C..._t3_B078RTXMXH

By default with cheap stuff do not trust ratings, buy 2-3x what you need, and account for startup inrush.


Samlex would be in the middle, but maybe susceptible to salt corrosion.
john61ct is online now   Reply With Quote
Old 06-03-2019, 16:18   #5
Registered User

Join Date: Jan 2017
Posts: 11,838
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by john61ct View Post
Victron Energy Orion 12/12-30A (360W) Isolated DC-DC converter
Actually have lots of choices with Victron, https://www.victronenergy.com/dc-dc-converters
john61ct is online now   Reply With Quote
Old 06-03-2019, 16:47   #6
Marine Service Provider

Join Date: Jan 2012
Location: Lake Ontario
Boat: Douglas 32 Mk II
Posts: 2,753
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by Ortolan View Post
I have a Nova Kool fridge/freezer combo unit with a single Danfoss compressor which I have made many improvements to (include heavier wiring). It now works much better BUT it REALLY likes 12.8+ volts. By early AM, when voltage drops to 12.3, the fridge coldplate begins to defrost even though the compressor is running continuously. As soon as I start charging the battery, it immediately begins to frost up & cycle normally.

I am now thinking - is there a voltage regulator device which would output around 12.8 volts even when my battery drops to 12.3? (I realize the draw would increase).

If it would also reduce higher voltages to around 12.8, that would be an advantage when equalizing my batteries at a high voltage.

Russ
Hi Russ,

I sell, install, and service Nova Kool ice box conversion kits and have one in my boat.

I have never noticed any difference in performance between 12.2 Vdc and 14.2 Vdc.

You do have to assure that you do not have excessive voltage drop in cable and connections.

1. Measure the voltage directly at the battery terminals. (12.0 Vdc is fine)
2. Measure the voltage directly at the module terminals. (> first - 0.2 Vdc
3. If Vdrop is too high, troubleshoot the circuit in between. Check V-drop across all cable connections, and especially the breaker (which could have high Z contacts).
4. If V-drop is fine:
i) Ensure door/lid gasket seals well.
ii)Ensure good condenser ventilation.
iii) Ensure no module fault codes (LED).
iv) Try swapping module.
v) Increase charge until evapourator is frosted over most surface but not beyond discharge tube. (Takes 24 hours after adding each little bits of refrigerant). DO NOT OVERCHARGE.
__________________
ramblinrod
ramblinrod is offline   Reply With Quote
Old 06-03-2019, 17:42   #7
Registered User

Join Date: Dec 2009
Location: Australia
Boat: building Roberts Mauritius 43ft
Posts: 1,196
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by Ortolan View Post
I have a Nova Kool fridge/freezer combo unit with a single Danfoss compressor which I have made many improvements to (include heavier wiring). It now works much better BUT it REALLY likes 12.8+ volts. By early AM, when voltage drops to 12.3, the frid.......
Russ
Russ
When I bought my Adler Barbour Cold Machine (Danfoss compressor) I wasn't asked whether I wanted 12V or 24V because the unit worked on either.

Since then I read it works better on 24V "as it is too energetic on 12V". At the time I wondered exactly they meant by that but since then I haven't been able to find the Instruction Manual(?) or any other article where they used that exact wording.

I am not surprised it works markedly better on higher voltages.

SKU number 9108777973

Model CU Adler Barbour Unit
US Item Name 755400000
Model on label CU-100,SELF SEAL QD,AIR 12V
Product Description Condensing unit, air-cooled 12/24V DC

NOTE: The BD50F compressor requires a Power Module to run. The same power module is used for 12vdc or 24vdc systems. The module must be purchased separately from the compressor. There are four types of modules to choose from, the standard power module (010-1175), the Adaptive Energy Optimizing (AEO) module (010-1176), the High Start Current module (010-1178) and the High Performance module (010-1153). The AEO module is more energy efficient as the compressor will always adapt its speed to the actual cooling demand. The High Start module provides additional starting torque and is more dependable in starting the system.
coopec43 is offline   Reply With Quote
Old 06-03-2019, 17:47   #8
Registered User

Join Date: Jan 2017
Posts: 11,838
Re: Regulating Voltage to a Fridge

Works on 12V **or** 24V, usually just means auto-switching, not that it's OK at any voltage in between.
john61ct is online now   Reply With Quote
Old 06-03-2019, 18:23   #9
Registered User

Join Date: Dec 2009
Location: Australia
Boat: building Roberts Mauritius 43ft
Posts: 1,196
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by john61ct View Post
Works on 12V **or** 24V, usually just means auto-switching, not that it's OK at any voltage in between.

So it senses the voltage?

Yes here we are. "are designed for connection to 12V and 24V DC power supply and fo...."
coopec43 is offline   Reply With Quote
Old 07-03-2019, 03:16   #10
Registered User

Join Date: Dec 2009
Location: Australia
Boat: building Roberts Mauritius 43ft
Posts: 1,196
Re: Regulating Voltage to a Fridge

Regarding my Adler Barbour Cold Machine fridge/freezer I am still grappling with the set-up.

The Danfoss compressor can work on 12V and handle voltages up to 17V and exactly the same compressor when run on 24V can handle voltages up to 31.5Vk.

Is that correct?


Looking at Table 4 it won't work as a 12V if the input voltage exceeds 17V. It will work as a 24V if the input voltage exceeds 22.7. Then Fig.3 gives the standard battery protection settings.



August 2011 compressors.danfoss.com - DEHC.EI.100.M6.02 / 520N0312

Instructions
Electronic Unit (Automotive Applications) for BD35F Compressors, 101N0600, 12-24V

The electronic unit is a dual voltage device. This means that the same unit can be used in both 12V and 24V power supply systems. Maximum volt-age is 17V for a 12V system and 31.5V for a 24V power supply system.


http://files.danfoss.com/TechnicalInfo/Dila/06/bd35f_automotive_electronic_unit_101n0600_12-24vdc_08-2011_dehc100m602.pdf
coopec43 is offline   Reply With Quote
Old 07-03-2019, 04:02   #11
Registered User

Join Date: Jan 2017
Posts: 11,838
Re: Regulating Voltage to a Fridge

Yes, senses voltage at startup to set which mode it's running in.

Solar controllers do the same, why the bank must be connected before the panels come online.

And different components / boards within the system may have different tolerances.

Troubleshooting those may well be a good idea.

But if it all works just right at say 13.8V, giving it exactly that, coupled with an LVD to protect the bank is neither difficult nor expensive.

Then you can get the fundamental root cause problem fixed later on when it's convenient.
john61ct is online now   Reply With Quote
Old 07-03-2019, 04:24   #12
Registered User

Join Date: Dec 2009
Location: Australia
Boat: building Roberts Mauritius 43ft
Posts: 1,196
Re: Regulating Voltage to a Fridge

QUOTE: Yes, senses voltage at startup to set which mode it's running in.

Solar controllers do the same, why.....UNQUOTE

Thanks John.

Solar controllers/panels are the next matter I want to consider. I notice there is a highly relevant thread on the forum right now.

But one thing at a time...
coopec43 is offline   Reply With Quote
Old 07-03-2019, 05:43   #13
Marine Service Provider
 
witzgall's Avatar

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,900
Re: Regulating Voltage to a Fridge

Others have said, I will repeat:

The Danfoss modules are very sensitive to low voltage. Check the voltage AT THE MODULE, nowhere else. If it is below spec when your house voltage is low, meticulously check all of the wiring and connections, and upgrade if needed. Even if this turns out to not be the issue, it is not wasted effort. I have seen many issues with refrigeration come down to this wiring.

EDIT: Thinking further, these modules can run on very low voltage, if set to do so. Down to 9.x volts I think. If your system is not cutting out (do you have an idiot light on the system, the module supports this and would show cut-out) then suspect something else.

Chris
witzgall is offline   Reply With Quote
Old 07-03-2019, 06:30   #14
Marine Service Provider

Join Date: Jan 2012
Location: Lake Ontario
Boat: Douglas 32 Mk II
Posts: 2,753
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by coopec43 View Post
QUOTE: Yes, senses voltage at startup to set which mode it's running in.

Solar controllers do the same, why.....UNQUOTE

Thanks John.

Solar controllers/panels are the next matter I want to consider. I notice there is a highly relevant thread on the forum right now.

But one thing at a time...
Absolutely,

When I talk to customers about adding refrigeration, one of the first questions is, "Do you plan to use it when not connected to shorepower, and if so, how many days in a row?"

If "No" or "< 12 hours" (a day sail) existing energy production systems will likely be just fine.

If the answer is "Yes" and "> 1 day", we immediately review the house bank and charging systems.

RE: Avoiding Battery Murder.

You need to avoid taking FLA batteries below 50% state-of-charge (SOC), except in an emergency. You also need to return them to 100% SOC as quickly as possible. Forays below 50% and < 100% SOC immediately after, takes life expectancy off the batteries. The deeper the discharge and the longer below 100%, the more their life is shortened.

To keep a close eye on the batteries you can install a battery monitor (a must for LiFePO4) or just use battery voltage for FLA (with no residual charge or heavy load on the batteries). It may depend a bit on manufacturer, but 12.75 Vdc = 100% SOC and 12.15 Vdc = 50% SOC, works well for most.

(A $10 Ebay digital panel meter is vastly superior for accuracy and resolution, compared to most small analog panel meters)

Once you gain some experience with the system, you will learn what the morning SOC must be, in combination with the expected alternative energy production for the day, before requiring the alternator.

With this ratio our alternator charging rule is:

12.2 before the sun,
Ready for a day of fun,
12.2 and mostly cloud,
Fire her up, it will be loud,
12.8 just after set,
All our energy needs are met.

The first mate and kids can pick up on this little ditty in no time.

For FLA batteries, I have found the following Consumption / Production ratio works very well:

Per 100 A-h or daily energy consumption:
  • 300 A-h battery capacity
  • 30 A shore power charger
  • 80 A alternator
  • 400 W of alternative energy production

RE: Alternative energy production. Solar is great in that it is silent and non-mechanical and (good quality, properly installed) panels will pretty much last the life of the boat with little or no maintenance.

If the vessel will be in an area where there will be adequate wind (> 15 knots > 8 hr/day) then it makes sense to combine solar and wind in your alternative energy allotment.

(It can be tricky to mount a wind generator where it will not shade the solar panels and possibly result in a net daily production loss.)

With just solar, you will find on average that you will have adequate power about 5 days out of 7. For the other 2 days, you will need to generate power by alternator for about an hour 1 day, and about 2 hours the other.

With wind power, you will likely only need to run the alternator for an hour 1 day out of 7. (You may need to add another 100W of solar, to make up for wind generator shading.)

If you live aboard, and will rarely be connected to shore power (e.g. 1 day out of 7 for 3 years or more), you may wish to consider LiFePO4 batteries instead of standard FLA.

Some may tell you that you will need only half the capacity of FLA, but I disagree. To have sufficient reserve capacity (to avoid firing up the alternator at inconvenient times) I recommend 240 A-hr min, for the above ratio.

Anyway, good luck with your fridge; I recommend investing in alternative energy production as soon as you can, if planning to anchor out a lot.

Having a cold beverage while pulling a lobster out of the freezer, and not having to worry about batteries, makes cruising life very civilized. ;-)
__________________
ramblinrod
ramblinrod is offline   Reply With Quote
Old 07-03-2019, 07:11   #15
Marine Service Provider
 
witzgall's Avatar

Join Date: Oct 2006
Location: Eastern Shore, MD
Boat: Camper Nicholson 44 Ketch
Posts: 1,900
Re: Regulating Voltage to a Fridge

Quote:
Originally Posted by ramblinrod View Post
RE: Avoiding Battery Murder.

You need to avoid taking FLA batteries below 50% state-of-charge (SOC), except in an emergency. You also need to return them to 100% SOC as quickly as possible. Forays below 50% and < 100% SOC immediately after, takes life expectancy off the batteries. The deeper the discharge and the longer below 100%, the more their life is shortened.
I am concerned a bit about the wording above, specifically the call to only take batteries below 50% in an emergency. The rest of the statement is true, but we have found that occasional dips below 50% are not very detrimental to the overall longevity of the batteries. What I have seen, is that boaters become stressed out if they ever see the % drop below 50% The duration of time the batteries are left below 50% is a much more important factor, in our (Balmar's) experience. A few hours is not a big deal in these situations. Leaving SoC below for longer than that does start to sulfate batteries more so. All of this is predicated on accurate SoC values, based on the actual battery capacity as it ages.

Chris
__________________

witzgall is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
thomasow' SAR and regulating charge current w/ SoC john61ct Electrical: Batteries, Generators & Solar 47 23-01-2019 10:24
Alternator not regulating charge Mike OReilly Electrical: Batteries, Generators & Solar 62 20-09-2018 13:05
Watermaker - Pressure Regulating Valve ohanasailing Plumbing Systems and Fixtures 16 19-11-2015 18:55
Low voltage vs higer voltage solar Singleprop Electrical: Batteries, Generators & Solar 11 06-07-2015 19:35
Regulating Hot Water Temperature By Invitation Plumbing Systems and Fixtures 4 11-12-2008 11:38



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:04.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.