FYI: New Danfoss BD35/50 Control Module

[senormechanico]

Re: being able to save, print etc. an image from a scope, it's nothing new.
I have a portable dual trace DVM Fluke ScopeMeter from the late '90's that can do that.
When I purchased it, it was the absolute top of the line, but its tech support has been long since discontinued by Fluke. (grrr)
When the backlight panel slowly died, I inquired about a repair.
Fluke basically said, "Oh, that old thing? Buy a new $$$$ shiny thing from us."

I bought some backlight material from eBay and fixed it myself.

[a64pilot]

Originally Posted by senormechanico

Re: being able to save, print etc. an image from a scope, it's nothing new.

For you maybe not, my use of scopes ended when TVs still had tubes, and remote controls were an option, I haven’t touched a scope since my enlisted days, and then it wasn’t my job, just a hobby and I had access to a rich uncle’s.

However if that was a scope image from his compressor starting it sort of answers the question of whether or not there is a current spike or not, and if it was observed for awhile, it ought to not be hard to determine if it starts at a low RPM and then speeds up, or if it starts at the RPM set by the resistor in line with the thermostat.
It just may be that unless they are started with lot of preexisting pressure on the high side, they may not be hard to start?

If he has the equipment it looks like he does, then maybe he can tell us?

[a64pilot]

Since we have the experts here a question if you don’t mind.
I have a .5 amp Noctua 120mm fan blowing quite a bit of air onto my system as pictured.
Is it doing any good, or just wasting a half amp?
I think it may help, but don’t want to just waste power.

[senormechanico]

It's best if you can duct new air into the space and duct the old air out.
My BD35 keel cooled system has no fan and barely fits the space it's in, so I bring in the new air from a slot under the fridge and blow out the warmed air into the cabin with a 120mm Noctua fan actuated by an adjustable snap disc mounted on the compressor.
It occasionally kicks on around 120 f. if the compressor is running on its highest speed.

[a64pilot]

Link to snap disk? I’d like to thermostatically control the fan.
It’s in my Lazarette, three or four people could fit down there, just not comfortably, so removing air isn’t as feasible.

[Richard Kollmann]

Originally Posted by a64pilot

Link to snap disk? I’d like to thermostatically control the fan.
It’s in my Lazarette, three or four people could fit down there, just not comfortably, so removing air isn’t as feasible.

Link to snap switch cooling fan.
Kollmann Marine

[a64pilot]

Original part number discontinued, but this one looks interesting
https://www.grainger.com/product/GRA...Also_Purchased

[Typhoon]

Originally Posted by Richard Kollmann

John, On these new modules I am also interested in what you see in the milliamp load change between terminals C and T in the first ½ second during start.

Hi Rich and Pete,

I will get that info as soon as I can and pass it on to you . I will post small videos .

Regards John
www.coldeh.com

[senormechanico]

I got mine on eBay.

https://www.ebay.com/itm/Supco-AT014...AAAOSw~OVWzikn

[Richard Kollmann]

Originally Posted by senormechanico

I got mine on eBay.

https://www.ebay.com/itm/Supco-AT014...AAAOSw~OVWzikn

It is important to remember these snap action switches are normally used in heating equipment so make sure the temperature range is correct for your application. I used the 110 closing and 90 degree opening model. On Cabinet refrigerators with static air condensers I used a tie wrap to hold switch to the coil.

[a64pilot]

You have to also make sure they are normally open and close at the set temp, just looking I have seen many that are closed, and open at the set temp.
I was thinking a drop of epoxy to glue it to the compressor, sensor down?

[a64pilot]

OK, just for fun a few hours ago I took my IR thermometer and measured the temp at the top of the compressor and it was 130F. It had run long enough to be at equilibrium.
I disconnected the 120mm Noctua fan I had blowing on it to cool it and led it run for a couple of more hours fan off, and took the IR thermometer and the temp was 128 F. Temp inside the Lazarette is in the high 90’s like 98, it varies by a few degrees based on location.
I think the 2 degrees is within error and not significant, so it tells me that in my installation, a fan doesn’t seem to help cool the compressor, least not the top anyway.
However it’s a Cool Blue and the design of a Cool Blue has the condenser fan blowing across the compressor, whether by accident or design the condenser fan may help cool the compressor even if it is blowing heated air from the condenser, or maybe a compressor isn’t cooled by air very well, it’s not like it has cooling fins.

Now hot is too hot for these little compressors? The side of mine where the HP line comes out was even hotter up to I think about 135 or maybe 138.

[senormechanico]

Originally Posted by Richard Kollmann

It is important to remember these snap action switches are normally used in heating equipment so make sure the temperature range is correct for your application. I used the 110 closing and 90 degree opening model. On Cabinet refrigerators with static air condensers I used a tie wrap to hold switch to the coil.

Sorry about that, I purchased one like you described.
I should have looked harder at eBay when I posted that link.
Mine is set to 120 close, and I've been thinking about adjusting it down a bit.

[OzePete]

Originally Posted by senormechanico

Sorry about that, I purchased one like you described.
I should have looked harder at eBay when I posted that link.
Mine is set to 120 close, and I've been thinking about adjusting it down a bit.

Fit it onto the Motor Driver Module, close at 120F there would be fine.

[missourisailor]

[QUOTE=a64pilot;2647168]... the condenser fan may help cool the compressor even if it is blowing heated air from the condenser, or maybe a compressor isn’t cooled by air very well, it’s not like it has cooling fins.
QUOTE]

The returning refrigerant plays a larger part in compressor cooling than air circulation. Hence, one of the reasons the return lines (low pressure lines) are insulated on almost every other system made...except marine refrigeration!