L3+ heat question

Discuss issues with mining rigs and connectivity issues with experienced Prohashing miners.
Raptor1
Posts: 4
Joined: Tue Oct 24, 2017 12:13 am

Re: L3+ heat question

Post by Raptor1 » Sat Jun 30, 2018 12:31 pm

cc4506 wrote:Question for someone. I live in Montana and most of us don't have AC here. My L3's are in the garage. We have several weeks where it does get in the 90's here, cools back in the evenings to the 40s or 50s. I was wondering at what point you shut your units down if you feel its getting to hot. I realize they have an auto shut down but would really prefer they not do that on me.

Thanks in advance.
90F is 32C
The T to watch is the chip temp = don’t push it beyond 80C = 176F
@ 90 F ambient, you don’t need to shut down your L3s.
But you should definitely move 230cfm per miner of ambient temp air (90F) using a box fan.
Foxx
Posts: 90
Joined: Mon Dec 04, 2017 6:20 pm

Re: L3+ heat question

Post by Foxx » Sat Jun 30, 2018 3:27 pm

Raptor1 wrote:
cc4506 wrote:Question for someone. I live in Montana and most of us don't have AC here. My L3's are in the garage. We have several weeks where it does get in the 90's here, cools back in the evenings to the 40s or 50s. I was wondering at what point you shut your units down if you feel its getting to hot. I realize they have an auto shut down but would really prefer they not do that on me.

Thanks in advance.
90F is 32C
The T to watch is the chip temp = don’t push it beyond 80C = 176F
@ 90 F ambient, you don’t need to shut down your L3s.
But you should definitely move 230cfm per miner of ambient temp air (90F) using a box fan.
with an L3, i wouldn't want to run it continously above 75C. also you can turn the frequency down and they will run much cooler, you will have to experiment though to see where it runs best. it does seem that your error rate gets quite a bit higher when you turn frequency down, but it is still doable.

we are having a really hot spell here, supposed to be in the 90's F through the 4th of July. I am quite sure my L3's will continue to run 24/7, albeit at a slightly reduced frequency.

can't run my S9's in this heat though. I have another set up for them.
Foxx
Posts: 90
Joined: Mon Dec 04, 2017 6:20 pm

Re: L3+ heat question

Post by Foxx » Mon Jul 02, 2018 2:02 pm

3 straight days of 95 F heat and these L3's are still rocking comfortably @ 212m frequency.

:)
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dnprod
Posts: 76
Joined: Tue Feb 21, 2017 3:19 pm
Location: Ontario, Canada

Re: L3+ heat question

Post by dnprod » Thu Aug 23, 2018 11:26 am

i too run a couple L3 in my garage in hot summer weather. it can get wayyyy over 30c in there. i have the door propped and locked open about 6 inches for some air flow, but its not enough on hot days.
the cost of any sort of active cooling will negate the low profitability of these units, even box fans are electric motors that consume overpriced electricity (we have nasty daytime electric rates.)

i bought a couple of outlet boxes from aliexpress that turn on/off based on a thermostat setting.
https://www.aliexpress.com/item/Tempera ... 57670.html

the box has two temp setttings, one is the high temp you want it to automatically switch off, the other is the lower temp where you
wish it to switch back on. i switch one off at 45c and on at 38c , and two degrees lower for the other box.
hopefully one box switching off sooner is enough to avoid the second box from switching off so i still have some hashing power going on.

i place the temperature probes for the boxes as far away and slightly lower than my L3 units. (hot air rises)

could probably run these a few degrees warmer but i dont want to completely stress my L3s over time or have some garage junk spontaneously combust. :D :o
i have come home from work late afternoon to find they are switched off. yes, it gets over 45c in the garage when the outdoor temp is in the 30s

my units are slightly overclocked. underclocking may be an option to avoid overheating too -- but i dont want to keep reconfiguring the clock speed depending on time of day or outside weather. max hash or none. 8-)

ps: these thermostats can operate in reverse manner, ie: switch on at high temp and off at low temp, so they could be useful for running box fans only when necessary to save on electric costs.
cc4506
Posts: 35
Joined: Wed Mar 28, 2018 10:07 am

Re: L3+ heat question

Post by cc4506 » Thu Aug 23, 2018 12:43 pm

when you turn down the freq does it lessen how much electricity they use?
sherm77
Posts: 19
Joined: Sat Apr 07, 2018 10:32 am

Re: L3+ heat question

Post by sherm77 » Fri Aug 24, 2018 11:50 am

Something that I did was directly vent my 6 L3+'s to outside using 90's adjustable elbows (6 inch) that come through a hole I cut in the mining building and then attached to that is some 6 inch dryer vent then attach to the output fan using aluminum tape (very sticky). It lowered the heat significantly in the building (12 ft x 32 ft).

I also have a 1600 cubit feet per minute exhaust fan that is temp controlled (set at 70 degrees F) that is near my gpu miners. I have 2 windows open 24/7 plus a window air conditioner at the opposite end of the building that is set at 80 degrees F. I have some ceramic filtered blowers & hose that I need to install so I can get fresh air into the building without leaving the windows open. Since I have 6 L3+'s (250 cfm each) plus the 1600 cfm exhaust fan, I need to make sure that I equal or exceed in the exhausting of the air to be sure I don't get negative pressure.

BTW, I'm not a a/c person, I'm in IT (30+ years), so I'm learning as I go. I've never lost any gpu's or L3+'s due to heat though. I burned up a few celeron processors on motherboards (gpu rigs) before I discovered hybrid cpu coolers. Worth the extra cost.
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