Samsung Refrigerator Power Supply Rating

[slimmm]

I have a RT21M top freezer refrigerator. The fridge area is very dark. The one light on top is not adequate. I am thinking about adding a led strip light by tapping into the 12v led light circuit.

Typical protocol is to determine adequate power supply driver for the light strip load. The fridge does not have a power supply driver per se, but a power inverter.

I suspect the power inverter has enough wattage for a small light strip since it powers the compressor, but I have no idea.

Can that power inverter handle an additional 7 watts; the expected load of the light strip?

I have sent this inquiry to Samsung support. 'Light is on... Nobody home.'

 

[dave_the_nerd]

Are you sure the light is an LED? I searched your model number, and it came with "RT21M6213SG" as an autocomplete, so that could be wrong.

But I ran it on a couple parts search sites and it came up with a 120v incandescent lamp as the replacement part. (Samsung part number, 4713-001172)

 

[slimmm]

Are you sure the light is an LED? I searched your model number, and it came with "RT21M6213SG" as an autocomplete, so that could be wrong.

But I ran it on a couple parts search sites and it came up with a 120v incandescent lamp as the replacement part. (Samsung part number, 4713-001172)

Absolutely LED. Correct part:

SAMSUNG REFRIGERATOR LED BOARD PART#DA41-00519A​

I got this one as spare, and work fine.

 

[mindless1]

This is a traditional mains AC (110V/220VAC) refrigerator/freezer, with a compressor, not peltier(s), yes?

If so, it is not an inverter (which is the opposite, an inverter converts DC to AC by inverting the waveform) but rather, the main power supply board simply has a switchmode AC-DC converter with at least a 12VDC output. It might just be to power the light(s), or it might also be to power other electronics like the logic board.

There is no easy way to know how much reserve current the power supply board can provide, short of finding a spec sheet or trying to reverse engineer to see which are the weakest rated discrete components and measuring how much voltage drop there is, powering the additional load.

It is not likely that the 12VDC power circuit is powering the compressor. If it were a small automotive fridge running off 12V vehicle electrical system, or child's novelty/toy fridge, 12V might power peltiers instead of a compressor.

Samsung support is not going to hook you up with an engineer who advises how to mod your fridge for another light. There are liabilities involved, you might electrocute yourself. No user serviceable parts, blah blah blah.

 

[slimmm]

This is a traditional mains AC (110V/220VAC) refrigerator/freezer, with a compressor, not peltier(s), yes?

If so, it is not an inverter (which is the opposite, an inverter converts DC to AC by inverting the waveform) but rather, the main power supply board simply has a switchmode AC-DC converter with at least a 12VDC output. It might just be to power the light(s), or it might also be to power other electronics like the logic board.

There is no easy way to know how much reserve current the power supply board can provide, short of finding a spec sheet or trying to reverse engineer to see which are the weakest rated discrete components and measuring how much voltage drop there is, powering the additional load.

It is not likely that the 12VDC power circuit is powering the compressor. If it were a small automotive fridge running off 12V vehicle electrical system, or child's novelty/toy fridge, 12V might power peltiers instead of a compressor.

Samsung support is not going to hook you up with an engineer who advises how to mod your fridge for another light. There are liabilities involved, you might electrocute yourself. No user serviceable parts, blah blah blah.

Yes regular full size friidge/freezer using 110v. However Samsung like most modern refrigerator cites 'Inverter Compressor Technology'. Inverter Technology (IT) is different than older 'conventional' compressor. This is a good explanation:

Inverter Technology In Refrigerators Explained | Cashify Refrigerators Blog

Modern refrigerators come equipped with Inverter Technology. Here is everything to know about inverter technology in refrigerators.

www.cashify.in

Essentially IT enables the operation of a variable speed compressor whose load can be efficiently changed according to outside and inside temperature; whereas a conventional compressor can only be operated full on, irrespective of environmental factors.

Also Samsung refers to the power control circuitry as 'Inverter Control Board''. There is only one other circuit, called the Main Control Board. The two boards are coupled together

There seems to be no conventional 12v power supply found in IC compressored fridges. To your point, this IC compressor is obviously not powered by 12v.; but no doubt the 12v power for the led lights emanates probably from a control board swithmode converter.

So I am just speculating the switchmode can handle an extra 7 watt load. Those boards seem to be common to various other higher end models that have a bunch more lights.

True, Samsung is not going to tell me how to do this mod, but just indicating the spec for the 12v load (without necessarily knowing why...) should not be outside the realm or reasonableness. (...sure...)

Anyway I have all the parts I need for this experiment. I will post back my results.

 

[mindless1]

The inverter tech for the compressor doesn't have much application towards the lighting power. All else fails, just add your own 12VDC wall wart PSU (or a current regulating AC/DC LED driver and series of LEDs alone instead of resistive current limiting like that pictured LED board has) for the additional light.

That's probably better in the long run anyway, not putting any stress on the existing Samsung parts which are bound to cost a lot more than a $5 buck PSU or current regulated driver plus a few feet of wire. Plus 3 LEDs you mount yourself on an aluminum plate, probably costs a lot less than that Samsung LED board as well, though if there are aftermarket sources for it, not necessarily... and this assumes you have a scrap of aluminum /whatever lying around.

 

[slimmm]

Doing the PSU route is the common approach, when there is an internal 110AC
source like an incandescent light socket. There is no internal AC source here; just the 12DC lead for the one light.

So the PSU route does not seem possible. Would not know how (or want) to rig an external PSU connection to the interior. The thought of semi-permanent wires protruding in and around and thru the fridge make me shudder.

Anyway went ahead and did the deed. Once I got the solder points and polarity correct... Success! Behold. And There Shall Be Light.
No flickering or dimming, so seems there is enough juice. Hopei it stays that way.

 

[mindless1]

Nothing you are stating seems true or makes sense.

There is clearly internal 110VAC. How do you think the power board gets its juice? Rigging an external is very simple, just plug it into the wall and route the wires where they don't get cut off by the fan. It's low voltage at the point if entry, not a safety risk.

Plus, running a SMPS beyond its design power, tends to shorten its lifespan even if it seems to work fine now. Granted, you probably only have the lights on for a few seconds at a time so that helps.

Carry on.

 

[slimmm]

OMG Of course there is VAC. I am referring to an accessible VAC source within the fridge compartment. I do not understand what you mean by routing the wires where they don't get cut off by the fan? Where is the entry point? Necessary to remove the fridge back panel? Necessary to remove ithe nterior compartment fan panel?

Seems a bit much. I must be missing something. Anyway I am happy with the results. Again the premise of this discussion was to determine the design power spec. That is not determined. So it is not known if the spec is exceeded; just speculation.

As stated, I think the same control board is used for several line models, some with multiple light arrays. Using some optimistic logic, I speculate the spec is not exceeded. And yes, the short intervals of operation are beneficial if not the case.
Carrying on.

 

[mindless1]

As stated, carry on. There's more than one way to skin a cat... but, there's ways where you encounter more risk than others.

Mains AC voltage is present in the fridge at a bare minimum, where it connects to the buck power supply board that makes the 12VDC, and the compressor control board if it's not all integrated into one PCB.