I have several wind measurement systems running only on solar power (which works just fine). The problem is that I now must upgrade some of the systems with anti-icing anemometers (and some other stuff) and the solar power just won’t be sufficient enough.
The only solution in this case is a diesel-generator connected to a battery charger that charges a couple of truck batteries. Monitoring the voltage via the CR800 is not a problem, or at least I can´t see any problem with that. But having a generator going 24/7 unnecessarily is a problem, both regarding cost and maintenance. So is it possible to somehow program the CR800 to turn on and off this generator at certain time intervals?
新对话如下：
You can certainly monitor the battery voltage with the CR800 and at a predetermined level use a control port on the logger to trigger an event. This may be a more cost effective approach to keeping the system going then just turning the generator on and off at specific periods. We would need more details on the generator to try and help spec out all the hardware you might need to start and run the generator.
IslandMan
新对话如下：
Thanks for the answer.
Your suggestion of using the voltage level to trigger an event was a very good one.
We haven’t decided yet which generator to use. It will be a rather simple one which obviously uses an electric starter. But we´ll use something similar to this one: http://www.made-in-china.com/showroom/gas-generator/product-detailQqtJmjwEVicR/China-Diesel-Generator.html
Which information do you need by the way?
Basically the plan is to use a simple relay to trigger the generators electric starter. I can´t see any problems with mounting such a relay on the generator. The biggest issue for me is how to program the logger to do a certain action.
新对话如下：
I suppose things I'd want to ask questions about and plan for might be:
1. Does the generator require a continuous input to remain running or just a relay pulse? How do you turn off the generator.
2. Is there an output on the generator other than AC that you can monitor to make sure it's running?
3. I'd add something to monitor the generator start battery as well. You would need this http://www.campbellsci.com/vdiv10_1 to do so independently of the datalogger battery voltage.
4. How do you know when to shut off the generator, based on time, state of the battery? It's difficult to do it with just the battery voltage alone because when the generator is running you wind up monitoring the charge voltage which is up around 13 Vdc and not the actual charge state of the battery.
Assuming a solid stat relay is attached to C1 on the logger, the code can be simple, it's the what if's that get you.
Battery(Batt_Volt)
If Batt_Volt < 11 Then PortSet (1 ,1 )
If Batt_Volt > 13 Then PortSet (1 ,0 )
Hope this helps.
新对话如下：
Your answer did help me, and raised a couple of questions as well.
1. The generator only needs a relay pulse to start. My thought was to use an impulse relay (don´t know if that is the correct term in English) to both start and stop the generator. Something similar to this one: https://www1.elfa.se/elfa~eu_en/b2b/catalogstart.do?tab=catalog
Do you know which voltage/impulse the CR800 can send out to trigger the relay?
2. Not that I can think of. This is a problem, I still haven’t figured out how to monitor this part of the process. I suppose one could use a thermostat? We will anyway mount a thermostat that will trigger a fan that cools the generator (all the equipment will be mounted inside a container).
3. That’s a good idea. I will sure look in to that solution.
4. This is one of the reasons, when I think of it, I would like to use a time interval rather than the voltage level to trigger the generator. I know that running the generator for one hour will give me enough charge to the batteries for at least 4 operating hours. The safety margin here is above 100% (if the generator won’t start the “first time”). The other reason why I would prefer to use a time interval is that a diesel generator can be hard to start in cold conditions, because of that I want it running for something like 5 to 6 times during a 24h period.
The code seems simple enough, although I don’t know anything about things like that. I assume one could write a code for time intervals as well?
新对话如下：
1. I cannot see the link you posted regarding the relay any longer, the "session timed out". Depending on the input required by the generator, you can use:
http://www.campbellsci.com/sdm-cd8s
http://www.campbellsci.com/sdm-cd16ac
http://www.campbellsci.com/a21rel-12
CSI sells a Crydom solid state relay that works with the Control ports. Model number is 7321 but I can't link it here.
2. Perhaps it's as simple as a small AC Relay. When the generator is on, it closes the relay and you can connect the contacts to +5 and a control port to monitor. Note, there are only 4 control ports on a CR800 that you can read/write.
4. It would be simple to code the controls to operate over specific periods each day. I think you still want to have feedback per suggestion in 2 that monitors that the generator in fact has started and is running. This way you can put some logic in that if the generator fails to start you can hit the pulse again to start. You could even monitor the temperature of the generator and toggle the fan on and off.
For rely on = generator on, rely off = generator off
'Turn the Generator on at 6AM
If TimeIntoInterval(0,6,Hour) Then PortSet(1,1)
'Turn the Generator off at 7AM
If TimeIntoInterval(0,7,Hour) Then PortSet(1,0)
新对话如下：
You probably want to monitor the battery voltage and turn the generator on when the batteries reach something like half capacity. Then measure the charge current and turn the generator off when the charge current drops to some constant value.
You could measure amp-hours in and out of your battery pack and return 110% of them like some golf cart chargers do, or other exotic things, but voltage for on and current for off will pretty much cover you.
新对话如下：
Hi,
want to do the same. But i want to turn off the diesel after 8 hours running. So i want to build in a timer.
but i have no idea to porgram it.
now i do:
solidstate(3) = 1
If Powersupply_V(1) < 25.20
ElseIf Powersupply_V(1) > 28.80
solidstate(3) = 0
EndIf
where can i now insert a time. i don't want to switch off the diesel at 28.8V only after 8 hours.
thanks in advance.
新对话如下：
bsssc,
I like to use "counters" for this type of timing. Here is the logic I came up with:
Public DieselCounter As Long, DieselON As Boolean
If DieselON = false Then 'if the generator is OFF
If powersupply_v(1) < 25.20 'check voltage threshold, if threshold is met then
solidstate(3) = 1 ' turn generator on and
DieselON = true'change status to indicate the Generator is on
EndIf
EndIf
If DieselON = true Then DieselCounter = DieselCounter +1 ' increment this every scan while the generator is running
If DieselCounter >= 2880 Then 'assuming a 10 second scan, 8 hours = 2880 scans
DieselON = false 'change status to indicate the Generator is off
solidstate(3) = 0 'turn generator off
DieselCounter = 0 'reset timer
EndIf
新对话如下：
Hi,
I have a soloutin now with the timer.
i start the timer after 25.2V are reached.
if the Voltage is over 25.2V the timer will count to the end and stop the solidstate
thanks
