Anyone familiar with samsungs terminalogy and electronics?

[paul_h]

Samsungs use a part they call a NTC, it looks like a huge varistor and is inline with the power circuit running the compressor, capacitor and soft starter.
They often just blow when the run capacitor dies
They not only use them on their PCBs but also on flying leads between the run capacitor and neutral.

Anyone know what they are and where to get them from?
I'm trying to repair them in the field rather than order parts from samsung (which always takes months) when I come across ones blown just because the run cap dies?

Here's a picture, I'm aware it has CNT written on it, but it is refered to in all the samsung manuals and printed on the PCBs as an NTC device.

[l'robot]

These are thermistors. NTC stands for Negative Temperature Coefficient. They are thermally sensitive resistors which change resistance due to ambient or internal temperature. They usually have a rating at 25c marked on them.

[paul_h]

Cheers.
Do you know why samsung use them in the compressor power circuit(never seen them in any other brand), why do they usually explode when the run cap dies?

[l'robot]

You will find them on PCB's from LG, Haeir etc, although usually smaller. They blow due to internal rise in temperature.

[Stev]

Cheers.
Do you know why samsung use them in the compressor power circuit(never seen them in any other brand), why do they usually explode when the run cap dies?

They are used to limit start up current. The current causes the thermistor to heat up and the resistance decreases. By the time the resistance has dropped, the back emf in the rotating compressor should have reduced the demand for current.

If the capacitor has failed and the compressor does not start, the current increases as the thermistor heats up and eventually overloads it.

The big problem with replacing them is finding a suitable replacement. I have started collecting old pcb's as a source of spare parts.

[paul_h]

Thanks all for the explanations.
I'm still looking for some electronics/electrical place to supply them, as I said samsung are slooooow for parts.

Thanks stev, i've done the same, saving PCBs for capacitors, fuses, relays and varistors etc.
Though it's hard to find a samsung PCB that hasn't got these NTC things blown, these and the large ceramic resistors are the first thing to blow, so even though I have a bunch of PCBs, I don't have these and will never have any of these things as spares unless I get a supplier of new ones.

[superswill]

paul

try dropping these people an email

wrong side of the water but iam sure they would ship

http://www.willow.co.uk/index.html

[Brian_UK]

Or here, from the USA
http://www.ibsstore.com/scripts/prod...?idCategory=71

[paul_h]

Thanks.
I guess I have to work out samsungs specs, then I'll look at trying to find a supplier.
Now I know what I'm looking for and why it's there now
Do they mainly get used in soft starters?
Just asking because samsung are the only manufacturer that make their own soft starters for our market and that use NTC protection.
Panasonic and other brands used locally made retrofitted soft starters (quick start and hyperstart) that don't use NTC protection. Fujitsu made their own soft starter for our market that had no NTC either (unless it was internal to their little black box).

Do you guys have soft starters and NTC devices in samsungs? I've always heard soft starters on small a/cs are unique to only a few countries like australia and france, I don't know if you have them there.

edit:
Soft starters a real PITA and very common faults down here.
It's fun when you have a burnt out one on a POS generic made in china brand that you don't have a parts supplier for though.
I've got a "Blueway" in my file that needs a soft starter PCB too...
Might just chuck in a locally made hyperstart like sharp and panasonic use for that blueway.

[superswill]

Thanks.
I guess I have to work out samsungs specs, then I'll look at trying to find a supplier.
Now I know what I'm looking for and why it's there now
Do they mainly get used in soft starters?
Just asking because samsung are the only manufacturer that make their own soft starters for our market and that use NTC protection.
Panasonic and other brands used locally made retrofitted soft starters (quick start and hyperstart) that don't use NTC protection. Fujitsu made their own soft starter for our market that had no NTC either (unless it was internal to their little black box).

Do you guys have soft starters and NTC devices in samsungs? I've always heard soft starters on small a/cs are unique to only a few countries like australia and france, I don't know if you have them there.

edit:
Soft starters a real PITA and very common faults down here.
It's fun when you have a burnt out one on a POS generic made in china brand that you don't have a parts supplier for though.
I've got a "Blueway" in my file that needs a soft starter PCB too...
Might just chuck in a locally made hyperstart like sharp and panasonic use for that blueway.

PM me as we know i'am samsungs UK best friend,i will email them and ask your questions

[nike123]

Just asking because samsung are the only manufacturer that make their own soft starters for our market and that use NTC protection.

Is there any regulation in Australia forcing use of soft starter? I don't see any reason for soft starter in small domestic split systems. And I could tell at least one against.
I would bypass that circuit if compressor relay is capable to withstand 5-6 times FLA, or install one relay which is capable.

[paul_h]

Yes it's regulations that units higher than 6kw cooling capacity (ie. 2.5HP+ compressor motors) have soft starters here.

That's why I was asking is soft starters are commonly used in european splits, as I've heard it's only australia and a couple of other countries they are regulated to use them.

Some a/cs just use a small PCB for soft starters, or a small box.
Others like larger samsungs have a huge collection of relays and resistors dedicated to it which takes up the whole space above the compressor, a 15cmx20cmx30cm box.

[El Padre]

Hi Paul,
Merry Xmas to anyone that is online, here in the UK almost every single split that is sold has an inverter driven compressor, this has been the case for a few years now.

Regards
El Padre

[nike123]

Yes it's regulations that units higher than 6kw cooling capacity (ie. 2.5HP+ compressor motors) have soft starters here.

Do you all have maxigraph installed on electric consumption counter? We have here current limitators ( in fact very slow fuses) who easyly overcome starting current from compressor of domestic split systems.

[paul_h]

Hi Paul,
Merry Xmas to anyone that is online, here in the UK almost every single split that is sold has an inverter driven compressor, this has been the case for a few years now.

Regards
El Padre

Yes, that is the case here too, inverters became an option many people started to use about 4 years ago, and now, almost every single split is an inverter.
But that means a/cs up to about 4 years old, some were not inverters. And a/cs more than 5 years old, most were not inverters.
So there's a lot of soft starters out there to repair.

Nike, no meters or maxigraph or any other reasons why we have soft starters, they are just required by law.

1.10.1.4 Limitations - Motors

The starting current of motors, which is significantly higher than running current, can cause a significant fluctuation of the supply voltage. Motor installations with associated starting/control devices must be designed to ensure that the starting current will not cause the reduction in voltage measured at the point of supply to exceed 5% for more than 20 milliseconds.

Table 1.3 provides a general guide for different types and uses of motors.

In areas limited to 230/460 volt supply, contact the electricity distributor for advice on special supply arrangements.

Table 1.3: Limits of Motor Starting Currents
Motor Type
Starting Current (A)
Single Phase, 230V
45A