db50 danfoss compressor power consumption

Submitted: Friday, Apr 21, 2006 at 09:58
ThreadID: 33119 Views:10424 Replies:7 FollowUps:18
This Thread has been Archived
I'm chasing the power consumption of the danfoss db50 compressor running a 390litre fridge on 24v's can anyone help?? It's in queenslands climate as well.
Back Expand Un-Read 0 Moderator

Reply By: timber - Friday, Apr 21, 2006 at 10:22

Friday, Apr 21, 2006 at 10:22
have a look at this site, their Tech Help may be able to help out.

www.rparts.com/index.asp
AnswerID: 168265

Reply By: GaryInOz (Vic) - Friday, Apr 21, 2006 at 10:39

Friday, Apr 21, 2006 at 10:39
Mentioned elsewhere on a fridge comparison thread here recently, 75 watts at 100% duty cycle. At 24 volts near enough to 3 amps.
AnswerID: 168271

Follow Up By: Member No 1- Friday, Apr 21, 2006 at 11:18

Friday, Apr 21, 2006 at 11:18
doubt it gary...
its on a 390 litre fridge....i guessits a domestic fridge that has been converted or maybe even a waeco?

i would reckon somewhere around 6 amps at -20°C rerigerating temp in Qld ambients and i assume it has a freezer.
0
FollowupID: 423575

Follow Up By: Geoff M (Newcastle, NSW) - Friday, Apr 21, 2006 at 11:31

Friday, Apr 21, 2006 at 11:31
Hi Nudie,
I think Gary may be referring to the values I posted on my 110 Litre Waeco tests.
It does run at around 75 watts in this cabinet. The only comment I'd make is the actual BD50 compressor shouldn't/wouldn't/can't draw much more than my stated 75 watts without overloading and letting the smoke out.

Geoff.
Geoff,
Landcruiser HDJ78,
Grey hair is hereditary, you get it from children. Baldness is caused by watching the Wallabies.

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 423576

Follow Up By: Mad Dog (Australia) - Friday, Apr 21, 2006 at 11:49

Friday, Apr 21, 2006 at 11:49
They are a variable speed compressor so cant they just crank the speed up which will of course will increase the current.
0
FollowupID: 423581

Follow Up By: Member No 1- Friday, Apr 21, 2006 at 11:54

Friday, Apr 21, 2006 at 11:54
yes ...that is correct for around 100 litre. but they are speed adjustable and to get more refrigeration duty from the compressor to suit larger cabinet you select the next best suited speed ...this of course ups the amps
based on the tech data at standard design conditions 32 ambient/-23.3 refrigerating temp:
speed 2000rpm it does 34.9 watts refrigeration and consumes 2.8 amps
speed 3500rpm it does 59.1 ditto and consumes 5.2 amps

0
FollowupID: 423582

Follow Up By: Member No 1- Friday, Apr 21, 2006 at 12:03

Friday, Apr 21, 2006 at 12:03
the figures i posted above are 12 volt ratings so one must halve for 24v so your about right geoff

I knew what I was thinking ...no one else did
0
FollowupID: 423583

Follow Up By: Member No 1- Friday, Apr 21, 2006 at 12:04

Friday, Apr 21, 2006 at 12:04
that makes my 6 amps wrong
0
FollowupID: 423584

Follow Up By: Geoff M (Newcastle, NSW) - Friday, Apr 21, 2006 at 12:05

Friday, Apr 21, 2006 at 12:05
Ahhh, thats right forgot about the variable speed bit.
Danfoss certainly put some thought into those compressor's.
Actually, Danfoss make a pretty handy VVVF drive for AC motors.

Geoff.
Geoff,
Landcruiser HDJ78,
Grey hair is hereditary, you get it from children. Baldness is caused by watching the Wallabies.

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 423585

Follow Up By: wheeleybin - Friday, Apr 21, 2006 at 20:09

Friday, Apr 21, 2006 at 20:09
The BD 50 is a 78W compressor which means it will use a maximum of 78 W at a prescribed temperature 1 to 1 cycle conditions.
The cycle conditions relate to the efficiency of the unit it is installed in.
If the unit is too big,badly condensed or insufficiently insulated it will then run longer and cycle less as the ambient increases but at 78W.
An increase in amps used exceeds 78W when the cabling is too small and the unit starves for power and tries to pull more load to compensate.
The only way to run a unit that big efficiently and economically is to use a BD 50 with a properly condensed Eutectic System and hopefully in an airconditioned house to keep the massive skin area temperature at a reasonable level.
Wheeley

0
FollowupID: 423685

Follow Up By: Member No 1- Friday, Apr 21, 2006 at 21:33

Friday, Apr 21, 2006 at 21:33
wheeley
what is "prescribed temperature 1 to 1 cycle conditions"?

the bd50 can consume a maximum of 109 watts at maximum design conditions ..which is 32 c ambient and -5 suction temp+

if condenser is adequate why do you need an airconditioned house

0
FollowupID: 423704

Follow Up By: wheeleybin - Saturday, Apr 22, 2006 at 07:00

Saturday, Apr 22, 2006 at 07:00
Ive just spent an age typing in a response and when I tried posting it it came up with "Not logged in" and now Ive lost it .
So Im sitting here looking at your baby face with blanked out eyes and silly smirk and I think Ill just go and sit in the corner with a hat on for awhile because I am an idiot.
Wheeley
0
FollowupID: 423747

Follow Up By: Member No 1- Saturday, Apr 22, 2006 at 09:26

Saturday, Apr 22, 2006 at 09:26
i do it often, so dont feel as though your on the outer....
0
FollowupID: 423760

Follow Up By: wheeleybin - Sunday, Apr 23, 2006 at 07:05

Sunday, Apr 23, 2006 at 07:05
Done the same thing yesterday.
Now Im back in the corner again.
Although this time I saved it to documents so now I have to work out how to cut and paste if that is possible for a blow in .
Is there a time limit on one finger typists taking too long with input.
Wheley
0
FollowupID: 423891

Follow Up By: wheeleybin - Sunday, Apr 23, 2006 at 07:27

Sunday, Apr 23, 2006 at 07:27
Just went into My Documents to print a copy and try again and all I saved was the "Sumit a follow up" header asking me to sign in so Ive lost it again.
Bugger back in the corner.
Before I go and put my hat back on can I ask.
If the BD35 produces 48W and the BD 50 produces 78W wouldnt your speed change figures you posted relate to the BD35 and not the BD50.
Wheeley
0
FollowupID: 423892

Follow Up By: wheeleybin - Sunday, Apr 23, 2006 at 09:01

Sunday, Apr 23, 2006 at 09:01
Hi No1
Ill have another go and this time if I bugger it Ill stay in the corner and sulk.

I was wrong in stating the draw at 78W as that is the Ref value and I concede to your Draw details.
The 1 to 1 i believe is what normal ref is expected to cycle 12Hrs in 24hrs 1 on 1 off.

Correct condensing is the critical factor and I think the unit in question is too big with inefficient insulation for the BD50 and more suited to the larger BD80.

The air con house reference relates to the ambient and with the massive wall area of the unit it would have half a chance of economical running in that environment.

Domestics normally are R5 rated at about 35MM and the BD50 in a 390L would be working its guts out.

I should have just shut up and read the later post on actual use experience as it is more explanatory but just does not answer the original post but I havnt either.
Wheeley
0
FollowupID: 423904

Reply By: Sam from Weipa Auto Electrics - Friday, Apr 21, 2006 at 12:22

Friday, Apr 21, 2006 at 12:22
The fridge has no freezer compartment its just a big fridge made by kelvinater I dont know if they convert standard fridge over or wether they manufacture them like this. I'm guessing were looking at a 70% duty cycle for queensland weather? am I correct in thinking this the fridge will only be getting opened in the mornings at lunch and at night times for cooking dinner.
AnswerID: 168287

Follow Up By: Ando79 - Friday, Apr 21, 2006 at 18:22

Friday, Apr 21, 2006 at 18:22
G'day Sam,

my Uncle and Aunty live in Weipa - Harry and Linda Martin. Say G'day to them for me if you know'em. Haven't seen them in ages.

Cheers,

Chris
0
FollowupID: 423672

Reply By: Member - Happy Little Camper - Friday, Apr 21, 2006 at 22:52

Friday, Apr 21, 2006 at 22:52
Hi Sam,

Found this pdf on www.danfos.com, it lists all the power consmption combinations of the 12/24V DB50.

BD50F_R134a_12-24VDC_04-04_Cd46b602.pdf

Driv'n Ivan
AnswerID: 168410

Follow Up By: Member - Happy Little Camper - Friday, Apr 21, 2006 at 23:05

Friday, Apr 21, 2006 at 23:05
Link to PDF didn't work.

If you left click it a danfos page opens
click "Data sheet/ Technical leaflet" and choose your comnpressor

Driv'n Ivan
0
FollowupID: 423723

Reply By: RobEG - Friday, Apr 21, 2006 at 23:54

Friday, Apr 21, 2006 at 23:54
Some random thoughts from my disorganised mind!

I have a place at Moreton where we are all on solar power and with some serious party goers refrigeration attracts a lot of attention.

In fact at the time I went solar I was the first to go 240V AC thru a sine wave inverter - mainly because of the lower cost.

But a lot have regular Kelvinators/Westinghouse/Fisher & Paylel units converted 24V DC and all the solar electrical guys say they are much more efficient than a 240 thru the inverter - both the DC motor and the losses thru inversion etc.

But generally the biggest I have seen converted to the bd 50 have been around the 220 litre but with freezer and these seem to work OK. ie reasonable cycle times but it is very dependent on the type of use or in simple terms how often it is opened.

The only larger size I'm can recall is a 290 litre Kelvinator (with freezer) owned by the neighbour but it had some Italian unit in it because the fridgee said the bd50 did not have the capacity to run the larger size. Now with the family on holidays (ie opened fairly often) this unit went 24/7 and danced around the floor from working that hard. And it cost a poultice.

So how does that help.

Well if you put it in a van as a mobile you will need around 6X80W panels just to run it and it will need top up on dull days. Being able to rotate panels if possible does greatly increase yield.

If it is in a stationary position I would probably recommend 240V and the inverter - cheaper and less drama - that size 1.8-2 kWh per day would cover fairly hard use.

Mate enough from me. I'm not a techo but I & my mates have a lot of ownership experience with this stuff and feel free to ask any questions - you won't get a technical answer but I can tell you waht happens in real life.
AnswerID: 168420

Follow Up By: Marn - Sunday, Apr 23, 2006 at 04:46

Sunday, Apr 23, 2006 at 04:46
Hi RobEG. Just wondering what you mean by rotating the panels?
Cheers Gerard
0
FollowupID: 423888

Reply By: wheeleybin - Sunday, Apr 23, 2006 at 07:13

Sunday, Apr 23, 2006 at 07:13
Hi Gerard
I am assuming he means tracking the suns orbit from east to west.
I am currently building an automatic tracker for my house lights.
Wheeley
AnswerID: 168532

Follow Up By: RobEG - Wednesday, Apr 26, 2006 at 01:01

Wednesday, Apr 26, 2006 at 01:01
Yeah wheeleybin - that is what I mean. Under the RAPS scheme most of us on the island have enough panels not to worry but a few still rotate. The auto ones are ok but many just put the four panels on a frame with a pole mounted on a VW hub Any would do but there are bulk of these laying around from old buggies across there). First thing in the morning rotate to the north east then at 9-10am rotate north then at 3pm rotate to north west. You have to be there to rotate and not the most convenient but very cheap but usually only required in high use periods. How r u going with yr auto?
0
FollowupID: 424361

Reply By: wheeleybin - Wednesday, Apr 26, 2006 at 07:27

Wednesday, Apr 26, 2006 at 07:27
Hi RobEG
Im up to the wiring stage and Ive run my trenches and conduits.
The unit is a small battery powered unit designed and successfully installed in WA.
You only need to manually adjust it three times a year to suit the orbit as the day to day work is all automatic.
It sits flat at night find the sun at morning and follows all day then returns to flat after sundown.
It you have a grinder,drill and welder you make the frame yourself and attach the kit.
The kit retails for $599 inc GST & Freight.
You should have it complete for under $1200.
If you like you can email me at nitramir@bigpond.net.au and Ill send you some photos.
BTW one kit has the capacity to run two arrays of over 4sqM each.
The designer used 4x64W= 256W Unisol that produced around 14A and I started with 6x66W= 396W Monos that produces 22A but now ive taken 2x66W out and included a 165W 24V Sharp in the middle and I should get 25A at 12V.
Wheeley.

AnswerID: 169006

Sponsored Links

Popular Products (13)