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Messages - BruceM

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Original Lister Cs Engines / Re: rpm limit
« on: October 14, 2021, 05:59:40 AM »
The Siemens product I've used before is a SIRIUS 3UG4 monitoring relay.
They are 24V AC or DC powered, will monitor AC or DC voltages or frequency (down to lister CS/SOM rpm speed) depending on the model.  I don't know the current prices, but they are likely a few hundred new. 

Just passing this on, sorry I forgot the details before.  I used this on my neighbors DES CS clone 8/1 setup, to protect the well pump, etc., from under or overvoltage in case of slipping belt or AVR failure.  I found it used on ebay.

Original Lister Cs Engines / Re: rpm limit
« on: October 13, 2021, 11:33:25 PM »
Seems you've done some good research and have a good plan, John.  Let me know if you need a hand.

One issue I've run into with ST generator heads is that the waveform distortions are bad enough to confuse most inexpensive (edit) non-RMS voltage/frequency monitors, particularly on AC frequency.  I solved that by switching to a Siemens RMS voltage monitoring relay, which has been problem free.  I recall that Siemens also makes a voltage monitor that runs on 24VDC, but can monitor 230VAC.  They are spendy but are available in a wide range of models.  So that's a possibility to look into if you have difficulty with the one you found.

Original Lister Cs Engines / Re: rpm limit
« on: October 13, 2021, 08:28:49 PM »
Good idea, Mike. There are some $55 diesel generator engine monitors on ebay, one at least that senses rpm down to 300.  You'd likely need a hall effect sensor and a magnet or 4 for the tach sensing.   I have zero experience with them.  Chinesium devices can be difficult as documentation is non-existent or unfathomable.  The issues would be how to power it without screwing up the SOM start/stop circuitry, and matching their tach input requirements, plus programming it.  I'll try to help if that's the way John wants to go. 

Original Lister Cs Engines / Re: rpm limit
« on: October 13, 2021, 06:23:21 PM »
Very helpful info, John.  I'm surprised that the minimal power of a voltage and power monitoring circuit would keep the SOM running once the larger load is removed.  Yes, sensing on the 24V side might be a good solution to avoid messing with the SOM start circuit.  There are DC voltage controlled relays which could then do the job. 

If you can connect on the DC generator side so that the relay is only powered when the generator is running that would avoid a load on your batteries.  (Upstream of a diode between DC generator and battery would do this.)  I'm not familiar with the SOM 24V charger circuitry so if you have a schematic/wiring diagram I can look at, that would be helpful.  Ideally we'd like 24VDC to power your overspeed sensing that is only present when the engine is running.

You'll have to test and monitor via VOM to see if DC sensing will reliably detect engine overspeed, once you've repaired your charge current limiting resistor.

If a rise in DC volts with overspeed doesn't look viable in testing, then we might look for an AC over frequency sensing relay powered by 24VDC to avoid the SOM start circuit troubles.  Frequency sensing relays are quite pricey, so I'd look at voltage sensing first. 

AC frequency sensing via Arduino is readily available, and the Arduino 5V could be powered from the 24V side, but hopefully we can avoid that approach.

I'm in central eastern Arizona, USA.

Best Wishes,

Original Lister Cs Engines / Re: rpm limit
« on: October 13, 2021, 12:20:08 AM »
If the voltage regulation on the genset is not too good, and AC (or DC) voltage rises when you overspeed, you might use a standard AC voltage sensing relay to trip your SOM solenoid circuit.  Watch AC (Or DC ) voltage while you force an overspeed.  I can probably find one that will work.  Are you generating 230V/50Hz or other?

There are some engine overspeed (tachometer) products, but they are not adjustable down to 650 rpm.

Original Lister Cs Engines / Re: rpm limit
« on: October 12, 2021, 09:21:42 PM »
I have rpm monitoring on my CS, for both over and under speed, with closing of the injection pump rack and lifting of the exhaust valve.  Rpm is sensed by a Cherry magnet/hall effect sensor near the spokes, rack and lifter via air cylinders, control via Picaxe 40X2 and hand wired board with logic level MOSFETs for air solenoid valve control.  Over temperature, oil high/low, and excessive vibration also cause an emergency shut down.

The same can be done today with almost no custom hardware via Arduino plus available interface boards.

The commercial engine rpm limit detectors I can find aren't suited for the CS due to it's low speed.  A Picaxe 08M IC (8 pin dip) could do it easily with a few lines of Basic.  Let me know if you need help.

Best Wishes,

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 27, 2021, 12:58:33 AM »
This afternoon I picked up the bargain bigger brother of my 12K BTU LG; the 18K BTU model from a nearby seller on Craigslist.

It has a bum evaporator side blower wheel, that is making some slight noise, and was pretty dirty, thus the new bargain price of $150.  I'd been watching it for a few weeks.

I ran it before taking it apart for a good cleaning and inspection; it draws 1600 watts while running the blower on high.  The compressor sounds good and the air was cool.  The total unit and the condenser seem huge compared to my 12K unit.  The fan motor on the 18K unit  is 276W instead of only 80W for the 12K unit.  One option is to use the 12K compressor on this chassis, with it's much larger fan and condenser coil.  The fan will have extra power for the evap cooling without a supplemental fan.

The question in my mind is if I reduce the power via cap tube/needle valve combo, can I still get good BTU levels.  Even more interesting would be if I can get acceptable performance at higher temperatures without adding an evaporative pre-cooler. 

I was surprised that this unit has an LG compressor, made in Korea. 

I just couldn't resist it for $150. 

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 25, 2021, 11:38:05 PM »
I took out the TXV that can't be adjusted without evacuating the system, and put in a needle valve plus the cap tube.
That let me restrict flow as temperatures climb to keep a constant 4.6 amps.

I tried wood then a metal cover for the condenser coil to restrict airflow so I could simulate a hotter day. The leaky stack of lumber gave better results; the metal cover seemed to cause greatly elevated current for the same temperature. Something about too much of the coil not being cooled at all.  The metal cover is shown in the picture.

As liquid line temperature got above about 95F, the BTU perfomance starts to fall off rapidly.  I'm able to get 13.6K BTU's at 90F,  13.0K at 94F, 10K BTUs at 102F.   Then it falls on it's face, and there's no chance of it not being adjusted properly, since I was doing it manually while watching compressor current, every so slowly.

So evaporative precooling is a must; my former LG window unit doesn't have the advertised 12000 BTUs, EER of 11.3 at 95F ambient at my elevation, at least.  (95F would be 110F liquid line temp at 15F approach).  I'm not getting anywhere near this performance at 95F equivalent liquid line temps.  More like 4000 BTUs.

I can likely live with the needle valve/cap tube combo, but could get the best cooling performance with an electronic expansion valve and custom microcontroller programmed to adjust for max rated amps.  They are cheap, but no one but me could maintain it or appreciate it. 

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 18, 2021, 11:35:00 PM »
Ha!  Bad headache today but maybe tomorrow I'll evacuate then charge and give the Emmerson a go.

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 18, 2021, 04:23:22 PM »
Sporlan is the highest priced TXV maker in the world, as far as I can tell.  Too rich for my low budget experiment with  higher suction temperature,  BPHE water cooler, I think. 

With a bigger budget I could nail down this floor cooling thing quite nicely; a bigger condenser coil with much better approach temp, slightly bigger compressor, increase the in floor water flow rate to 4 GPM via Lang D5 Strong pump to allow higher indoor humidity and add an evaporative pre-cooler plus air intake about 6 foot above ground level to reduce air inlet temps another 10F in the afternoon sun.   

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 17, 2021, 10:10:34 PM »
I can get the proper sized valve, with specs for suction temp of 58F,  from China-  in about a month.  They even have SAE flare connections available, which is nice if you need to replace the valve.
I'll look at the 1.5 ton units carefully.

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 17, 2021, 08:40:44 PM »
I'm having no luck finding an appropriate valve.  Lots of the 1.5 Ton, but not for R410A, 1 Ton.  I expect since all the smaller units have gone to inverter/electronically controlled expansion valve.  I'm visually exhausted, will try more poking about later. 

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 17, 2021, 05:00:46 PM »
The Emerson ANCEB-1-ZW-195 is apparently designed this way.  Not perfectly clear from their website but for the A series valves, the second letter, N, means non-adjustable.  It's in their economy series.  Thus the adjustment that isn't adjustable with the system charged.

Who knew such a thing existed?  Not me!

Now I've got to search again for an actually adjustable TXV with bleed, 1 ton, R410a. 

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 17, 2021, 04:26:02 PM »
No packing, the adjustment is deep inside the open cavity via 6mm allen key. Adjustable means they can figure out the turns for different models the hard way;  not ideal for an experimenter.

I wasn't expecting this kind of "adjustable".

Everything else / Re: DIY water chiller - reading suggestions?
« on: September 17, 2021, 12:44:51 AM »
I evacuated the system and put in the Emerson TXV today.  When pressure testing on nitrogen I had a surprise.  The cap that closes off the adjustment (6 mm hex key required) seals off the high pressure line as well.  I left it loose expecting to adjust leaked badly until I tightened it.  So you cant's adjust the thing unless you are willing to evacuate the system.  Not very helpful for my setup as there is no way to easily "dial in" the best performance.

I don't know if this is common or if it's why this Emerson model was so cheap and readily available. 

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