To Battery or Solar Controller?

[Groong]

Hi. I'm new to the Netonix switch. I will be replacing my ToughSwitchs with them. I'm using WS-12-250-DC (I purchased three of them).

Question 1: It says I should go straight to battery thus allowing batteries to drop down to 9V until switch shuts off. I'm on a 24V system. I know the switch reads up to 72V input so I'm assuming that when my batteries are being charged, the extra voltage does no harm to the switch. That being said, is it better that I just use the 24V load output from my solar controller and have a steady 24V's?

Question 2: If I go with the straight to battery option, what amp fuse should I have inline if I were using 8, 10, 12 gauge wire? Is the fuse to protect the wire (which is usually the case and I would use a higher amp fuse) or to protect the device in which I don't need as high?


On my first switch switch out (ha ha...) I will be powering (6) sectors (all 24V UBNT Prisms), and have (2) 24V fans that will turn on during the afternoon to keep the batteries cool and off in the evening/night/morning. I've turned the 24V fans into POE fans...I'm surprised I couldn't buy those but the Netonix switch is great for scheduling. I may create a rule that turns them on during certain temperature readings.

Currently running: netonix: 1.5.1rc4 on WS-12-250-DC

Thank you for any input!
Phil

[sirhc]

We recommend you hook the switch DIRECTLY to the battery bank with an inline fuse or preferably a breaker.

DO NOT SPARK THE CONNECTION when connecting and disconnecting the switch which is where a breaker is nice.

Hook the charger up separately

Often times the charging unit can not supply enough amps especially during inrush events and or dips during change over and the switch see this and reboots.

HOOK IT DIRECTLY TO BATTERIES AND THE VOLTAGE THE SWITCH SEES IS SMOOTHER AND DOES NOT JUMP AROUND.

If this site has electrical service add 2 new service ground rods to existing service ground rods and make sure to BOND service ground rods to tower ground rods.


99% of all WISP equipment damage is from ground current (I own a WISP)
Another common cause for damage is a shorted cable or incorrect POE option applied to device.

NEVER plug a cable into a port with the POE already turned on. The switch can detect shorted cables and prevent damage to the switch.

Here are some good posts on grounding:
viewtopic.php?f=30&t=2786&p=19279#p19279
viewtopic.php?f=30&t=1816
viewtopic.php?f=30&t=188
viewtopic.php?f=17&t=1786&start=30#p13447
viewtopic.php?f=30&t=1429

Read the posts above but the basics are as follow:

Tower ground rods must be bonded to electrical service ground rods HEAVY #2 wire.
I always add 1 or 2 “new” ground rods to older existing electrical services.

[Charlie]

Connect to the battery.
You can monitor the input voltage using SNMP to see how your batteries are doing. With an mppt controller the netonix will report a steady increase to 28v (85%) then it will go flat and at 100% drops down to about 27v until the sun goes down.

Overnight the voltage will slowly drop from 26v and then in the morning start rising again.

You want to set your equipment to start shutting down at 24.2v to 24v except your upstream connection to access the switch and still get the alerts /snmp monitoring out. Each time you switch something off, your voltage will rise by about .1 to .2V
At 23.8v your upstream connection gets shut off and at 23.5v the switch should go into hibernate mode to protect your batteries from being discharged below 30%

Set your switch to come back on at 23.8V and your upstream connection at 24.1V then start turning on other equipment again at 24.4-24.6v noting that each time you switch something on, the voltage will drop by .1 or .2v
This gives your batteries a good amount of amps to get some charging done before your radios start taking them away from the charging.

Some solar controllers will keep the load output voltage regulated which means the netonix wont be able to tell what the battery voltage is, and therefore as soon as you hit 30%, the controller shuts off the load output and everything just stops without warning.

Also be aware that adding a netonix to a solar site uses about 8 watts.

[Charlie]

I would use a 15 to 20 amp fuse for the 250 model. Sirhc can correct me if i am wrong on that.

[sirhc]

I would use a 15 to 20 amp fuse for the 250 model. Sirhc can correct me if i am wrong on that.

So the product description tells you that the switch will operate if you so desire:
Down to 9V delivering 150 watts or 150W / 9V = 16.7 Amps
Down to 12V delivering 250 watts or 250W / 12W = 20.8 Amps

So your inline fuse or "preferrably" a breaker of 20 to 25 Amps is needed.

WARNING: Discharging your batteries this low in an EMERGENCY will often require a truck roll with charger as most batteries require 10A per battery charger to recover batteries discharged this low but in an EMERGENCY you have this option to keep your site up as long as possible.

A breaker is better than fuse as you do NOT want to spark the connection when connecting and disconnecting the switch from the batteries as this ON - OFF - ON - OFF - ON of power can cause damage to the switch. MAKE SURE CONNECTION IS QUICK AND SOLID NOT SPARKED.

Here is a nice DIN RAIL 2 POLE DC BREAKER: https://www.tradezone.com.au/product/pg ... 23808.html

[sakita]

Just wanted to chime in on this topic... direct to battery = good.

One of our solar-powered sites (WS-8-250-DC) has had issues with the switch locking up (we'd lose communications to the site and have to truck-roll to power cycle it).

So, after multiple trips including checking the batteries, firmware upgraded, power input calibrated, and even swapping out the switch I read this post (and a few others with the same consistent advice). I hadn't been to the site myself and wasn't 100% sure but had it verified that it was hooked to the solar controller. So, I had the connection changed to direct to the batteries. Heaven forbid, follow the manufacturer's recommendation.

According to Netonix manager the site has been up two weeks so far with no issue.

A couple of interesting observations:

1) We have other sites that are connected to the solar controller with no issue.

2) The power graphs do look different between the battery-connected and solar-controller connected sites. My non-scientific observation is that the direct battery connection is smoother (cleaner / less variable) and my suspicion is that this is because the solar controller connection is being manipulated by the solar controller (and the solar controller manual indicates that it does do this).

So, again, direct to battery = good.