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Post by frostyfrank on Jan 30, 2014 14:44:35 GMT
... should I wait before I try to power this thing-up ? Scenario: 1932 DR 2 A 16, heard ti run in original owner's cellar before loading it up and bringing home. Had to remove the Refrigerating Unit to get it in the truck, and transported with the cabinet adn the RU laying on their "backs". Everything was well-padded, especially the evaporator. Poor thing rode around in the back of the truck for two weeks before I could get it unloaded. Finally got it out of the truck Monday (four days ago), brought it indoors, and put the RU back on the cabinet. It has been standing upright since. This morning, we tipped it onto a flat-bed, and moved down to the work-room, tipped it to un-load, and now it sits where it will be tested. Given that background, how long should I wait before trying to run it, and what should the start-up sequence be ? (Has the horizontal control box).  Thanks ! Frosty Frank |
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Post by ChrisJ on Jan 30, 2014 14:55:01 GMT
I would replace the heater or at least test the one that is in it before anything. Once the heater is working let it sit for a few hours especially if its cold before starting. DRs and CAs need the heater to work right. I found letting the heater run in my CA for even 2 hours wasn't enough when it was really cold in the room. After 4 hours it seemed to be happy.
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Post by frostyfrank on Jan 30, 2014 15:50:05 GMT
I would replace the heater or at least test the one that is in it before anything. Once the heater is working let it sit for a few hours especially if its cold before starting. DRs and CAs need the heater to work right. I found letting the heater run in my CA for even 2 hours wasn't enough when it was really cold in the room. After 4 hours it seemed to be happy. Questions: 1) Is there an "easy test" for the heater ? 2) How cold is "cold in the room" ? Work room averages 75* F (over-top boiler-room at work...) FF |
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Post by ChrisJ on Jan 30, 2014 16:04:25 GMT
Cold was 50s like my dad's basement.
75F as long as the machine sat in there long enough to warm up might actually run ok without the heater but not perfect. Easiest way to test a heater is to plug the machine into a watt meter. With the compressor off it should draw 10-12W give or take. I think my 12W heaters come up as 9 or 10W on my kil-o-watt meter even though they are drawing slightly more.
If you don't have a watt meter the heater should measure around 1000ohms.
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Post by frostyfrank on Jan 30, 2014 16:11:51 GMT
Can I just measure across the line plug with the control turned to "Off" ?
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Post by ChrisJ on Jan 30, 2014 16:24:17 GMT
Can I just measure across the line plug with the control turned to "Off" ? Good question, I would assume so but you might end up measuring leakage if wires are damaged. |
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Post by frostyfrank on Jan 30, 2014 18:57:45 GMT
It just read as an open circuit, so I assume the heater is dead.
How involved is heater replacement on a DR ?
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Post by cablehack on Jan 30, 2014 22:57:17 GMT
It just read as an open circuit, so I assume the heater is dead. How involved is heater replacement on a DR ?  I always apply thermal paste to the heater before insertion - it will transmit more of the heat to the oil, and will reduce hot spots on the heater which will cause early failure. |
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Post by ChrisJ on Jan 31, 2014 0:32:00 GMT
One reason I didn't use thermal paste is the typically stuff dries up over time. I feel when it dries up it will make the heater near impossible to remove.
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Post by cablehack on Jan 31, 2014 1:32:22 GMT
One reason I didn't use thermal paste is the typically stuff dries up over time. I feel when it dries up it will make the heater near impossible to remove. It all depends what you use. Silicone grease as was originally used with semiconductors won't solidify. I agree that some of the white pastes of today do, but others don't. I was in the fortunate position of having stocks of the stuff which I've been using for about 20 years, so could see how it performs in the long term. This is what I used on both my home made heater and the original GE type. The type of modern thermal paste I recommend is almost like a liquid. The stuff that's like a thick heavy paste can dry out. Having said that, it won't solidify to the point of actually becoming a permanent adhesive. Incidentally, I've used this kind on my solar hot water evacuated tubes which can run up to boiling point, and even after a few years the paste is easily separated despite being a bit dry and crumbly. Rust in the heater well and a tight fitting heater is also important. If it rusts in then things will get a bit awkward, but the thermal paste may also be beneficial as an anti seize compound. |
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Post by ChrisJ on Jan 31, 2014 13:18:14 GMT
The white silicone grease used on semiconductors is mainly what I have experience with. If you take apart any 1970s or 1980s electronic device you will find this grease dried up and almost solid. An example of this compound is Dow Corning 340 www.dowcorning.com/applications/search/default.aspx?R=104EN |
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Post by cablehack on Feb 1, 2014 4:44:41 GMT
Interesting to see that - 'non flowing' in their description would appear to support the characteristic of it solidifying. I certainly know of the characteristic that you describe. I'd probably give that substance a miss for monitor top heaters.
The silicone grease I've used is a clear substance which is really like grease that you'd use on a bearing (which I have done). The modern stuff I use is white and a bit watery. It's made by Unick Chemical Corp. Some of the very early constructional articles dealing with mounting power transistors (1950's) suggested using a smear of motor oil. Not as bizarre as one may think - the purpose of it is really to fill in the air gaps between the semiconductor and heatsink. I remember having to do heatsink calculations as a student, working out the surface area of a heatsink given a certain power, and permissible temperature rise. As the thermal transfer compound was between the two, its losses also had to be put into the equation. I'm glad those days are over.
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Post by ChrisJ on Feb 1, 2014 13:56:00 GMT
Yeah, they say its non-flowing yet that isn't entirely what I've found. I've used it on CPUs in PCs and have found the oily residue leaked out and ran down all over the motherboard. Found the same thing in the 250W amplifiers I built although I didn't really care so much in that as it just ran down the aluminum heatsink. What I don't know is if it caused a problem in the a PC or not. I had a motherboard failure and had no idea if it was related to the oily residue or not. I'm assuming not but who knows. This is the main reason I switched to the more expensive "Artic Silver" type compounds, they don't seem to do that. www.newegg.com/Product/Product.aspx?Item=N82E16835100007 |
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Post by frostyfrank on Feb 1, 2014 16:00:44 GMT
How much clearance is there between the heater bore and the heater capsule ?
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Post by ChrisJ on Feb 1, 2014 16:06:45 GMT
I think it depends on the machine. I ordered 12mm diameter heaters and they fit pretty good. I've heard 12.5mm might fit, but might not.
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