05-15-11, 02:08 AM | #11 | |
Apprentice EcoRenovator
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Quote:
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05-15-11, 08:08 AM | #12 |
Lex Parsimoniae
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How to set the heating mode?? (Inverter mini-split)
"you only need to energize the solenoid"..
I had been wondering how I was going to keep the Sanyo in heating mode. The 'Indoor unit' will be replaced by a refrigerant-to-water heat exchanger. The 4-Way Valve (connectors RV0 & RV1) will need to be 'Energized' or maybe left off? Notice that RV1 is the second Relay in the relay stack. (Note: T-Run/Test connector is in the center bottom of PCB). I'm betting the default power-up is Cooling mode. If that's true, I'll have to make a mod. If RV1 is hot after power up, I'll just unplug the connector. Or, if RV1 is off after power up, I'll need to jumper across the relay. (RV1 to AC2). (In this case, I would use an SSR as the jumper. So as to allow for DIY Defrost mode in winter). OR, If I'm wrong and the default power-up is heating mode. I'm Golden. One goal is to hack/configure the unit to power-up in the heating mode, as it's default. Then use the 'T-Run/Test' connector to start-up heating mode (remotely). If that hack-config is possible, then I could leave the unit powered on, to keep the crank-case oil nice and warm.. It the hack fails to work, and the T-Run has to be shorted before power-up, then AC power would need to be used to control the Off-On function. That would mean running a hot AC power line to the crank-case heating element. It's starting to look like this project might be possible.. ~~~ Recently, one poster had a bad install that was hard to figure out.. The mini-split would only run in Cooling mode. No matter that he had selected heating.?. His Electrician had wired the 230v mini-split with 115v !! And it cooled just fine.. So, maybe the AC2 (AC power source for the relays) was stone cold.?. And it needed to be energized ?? Makes me wonder if his crank-case heater was off too..?. |
05-15-11, 09:08 AM | #13 |
Journeyman EcoRenovator
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In your diagram for the Refrigerant Flow Diagram, what is a strainer and a muffler?
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05-15-11, 09:50 AM | #14 | |
Lex Parsimoniae
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I'll try google.. :)
Quote:
"Mufflers are designed to eliminate pulsation in compressor discharge line running to remote condensers. Mufflers have internal baffles designed for minimum pressure drop. These baffles change the velocity of the discharge gases passing thru the muffler. This reslts in a dampening effect on high frequency sound waves in the gases on high speed compressors. This also ircns out the pulsating waves in low speed compressors. " "Refrigerant strainer collects foreign materials and dirt in a refrigerant system at minimal pressure drop in order to minimize or prevent damage of control valves" etc. etc. |
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05-15-11, 10:08 AM | #15 |
Journeyman EcoRenovator
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On the strainer, I just kept getting stuff for boats..... Thanks,
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05-15-11, 10:29 AM | #16 |
Apprentice EcoRenovator
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The units I've tried out always run as default in cooling mode. You need to energise the 4-way valve solenoid for it to work in heating mode. On my unit I simply do this by connecting it in parallel with the power input. My units are either on or off so the solenoid gets time to energise to reverse the flow before the compressor has started up. It's a bit 'odd' when it shuts down, makes strange noises as the solenoid de-energises and the refrigerant flows back the other way causing a quick burst of cooling.
I thought about the possible problems this might cause but the unit must be designed to cope with this as it is exactly what would occur in a power outage. Nigel |
05-15-11, 08:52 PM | #17 |
Lex Parsimoniae
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Okay Nigel, I'm in a cold climate zone here, so maybe I should plan on being able
to run a defrost cycle sometimes. So, perhaps I'll plan on controlling the 4-way valve. I was just trying to learn how they work at this site: Heat Pumps First, I need to get the leak brazed. Once that's done, I should be able to figure out how to test the unit, making sure it will meet my needs. Hopefully, the T-Run/Test function will allow for a somewhat normal heating operation. Just saw this informative video on youtube. YouTube - Brazing with Nitrogen vs. Brazing without Nitrogen |
05-16-11, 10:34 AM | #18 | |
Supreme EcoRenovator
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Quote:
Since your other 24K BTU unit is already heating your house, your leaking unit, if you can get it running, would probably be capable of supplying 3 to 5 times as much energy as you actually need for DHW. So you could probably utilize some of that energy for your radiant heating which you already have in place. Your existing radiators were designed for feed temps in the 160 F temp range and will have a pretty modest surface area, so the lower feed temps from your ASHP (likely around 120 F) will not supply nearly as much heat as your oil fired boiler, but it should help some... -AC_Hacker
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05-16-11, 11:51 AM | #19 |
Lex Parsimoniae
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Yeah, I was thinking that we would be awash in abundant hot water during the summer,
and could use it for a little heating during cold weather. (Be great on laundry day) That extra heating would be possible, if I didn't buy a new storage tank, but used the old HS Tarm boiler (76 gallon water jacket), coupled to the old Sanyo, via a 'new' refrigerant-to-H2O exchanger. What we've noticed when using the free-flow valve on the upstairs baseboards, (without the circulator pump running) is anything over 100 deg F can provide some pretty good heating. I was a bit surprised. I figured they wouldn't be much heat, unless the water was over 140ish. The heat transfer rate is pretty slow. But leave it on a few hours and it does add to the overall comfort, especially in the Den (with all it's glass). I have a (mostly unused) circulator pump for the basement baseboard loop. (We have not heated the basement in the last 15 years). With some 'T' connectors & cut-off valves, I could easily connect into the Tarm water jacket, and use it's pump to drive a refrigerant-to-H2O exchanger. (1 SSR required). The water in the jacket isn't real clean. So the exchanger should be a low-clog type. Or, I could add a cleanable inline filter.. Do you have any suggestions for an Ebay exchanger? In normal full power heat mode, this Sanyo is rated to produce 36,000 BTUh.. But, if I can control the unit, I would like to keep it under 10,000 BTUh.. Just let it run longer at lower power usage. (More compatible to PV) |
05-16-11, 03:25 PM | #20 | |
Supreme EcoRenovator
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Quote:
Nigel's home brew HXs look pretty interesting, maybe you should try that? -AC_Hacker
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