Adding an additional VT question

Support
1

I obtained a Jameco 100061 and figured if I purchased a barrel connector to a 3.5 mm plug adapter I would be in business. But that did not work and created a warm electronics smell instead. I could not connect to the Iotawatt and had a green red red code when powered back up so I took it apart and looked at the SD card on my PC and the config looked fine to me so I put it back together and it worked. As a follow up I did change input_0 to a Jameco 100061 and it worked fine. I have since placed the JW-95001-NA back on input_0.

It looks like the failed restart was stuck after this “LLMNR responder started for hostname IotaWatt” since there were no additional entries.

I had an iotawatt at my last house and did not do anything dumb with it and obtained a lot of useful info. My new house has a double lug meter base with two panels and due to some weirdness I’m seeing I just want to keep track of more inputs.

Until I receive some constructive feedback on how to physically add a second VT I am going to wait. Everything is working fine and put back as it was.

2

The Jameco comes with a 2.1 x 5.5mm barrel connector to be used connecting to IoTaWatt. I’m assuming that because you changed it to a 3.5mm jack you plugged it into a CT input. When you add a second or third VT, you should be using the three-phase VT inputs on the back. Inputs 13 and 14 are dual purpose, so you use the VTinput for a VT and the 3.5mm jack for a CT. That electrical smell was probably the CT burden resistor cooking. At 20 ohms it will draw 450mA so no damage to the VT, but the resistor is not rated for anywhere near the 4Watts it would draw, si it was probably glowing red. Good chance you damaged it.

The good news is that if you use that input for a VT with the correct VT plug, it doesn’t matter if the CT burden is damaged.

3

I purchased the adapter separately and I set up port 14 before I plugged it in. The 3.5mm jack looks like a mono plug so it could be wrong, I’m not sure how the internal jacks are wired so I guessed the tip is one side and the rest is the other to make the AC connection. At this point I assume I did not plug it into 14(which would be deeply disappointing) or I shorted out the connector itself with the adapter plug? Do you know of a known good 2.1 x 5.5 mm to 3.5 mm adapter? The adapter I have fits great mechanically on both ends.

FYI, this is how my inputs were configured at the time:

	"inputs": [
		{
			"channel": 0,
			"name": "Input_0",
			"type": "VT",
			"model": "JW-95001-NA",
			"cal": 11.14,
			"phase": 0.74
		},
		{
			"channel": 1,
			"name": "Garage_Main1",
			"type": "CT",
			"model": "AcuCT-H100-200",
			"phase": 0.25,
			"turns": 4000,
			"cal": 200
		},
		{
			"channel": 2,
			"name": "Garage_Main2",
			"type": "CT",
			"model": "AcuCT-H100-200",
			"phase": 0.25,
			"turns": 4000,
			"cal": 200
		},
		{
			"channel": 3,
			"name": "WallConnector1",
			"type": "CT",
			"model": "AcuCT-H040-50",
			"phase": 1,
			"turns": 1000,
			"cal": 50
		},
		{
			"channel": 4,
			"name": "WallConnector2",
			"type": "CT",
			"model": "AcuCT-H040-50",
			"phase": 1,
			"turns": 1000,
			"cal": 50
		},
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		{
			"channel": 14,
			"name": "Input_14",
			"type": "VT",
			"model": "Jameco/100061",
			"cal": 11.68
		}
	],
4

See the docs here for how to connect and configure an additional VT.

YOU SHOULD NOT BE PLUGGING A VT INTO A 3.5mm JACK.

5

Wow I feel pretty dumb and overlooked there are two port 13 and 14, I have a 240v split phase and just want to watch everything due weird voltage drops. Some outlets have 108 vac and some have 115 vac and figured I could use two VTs to rule out any imbalance like a damaged line coming in. Of course phase A and B should be the same but I want to make sure. The Jameco 100061 is outputting about 9 vac according to my meter under no load and I cannot get anything to read on input 13 or 14. Do you think I burned something up?

I have my Tesla wall connector dumping 240 vac at 48 amps into my car and the voltage drops about 10 volts or so. I thought it was the wire to the 60 amp breaker but the main is dropping the same amount according to the VT on input_0. My car lists the voltage and current during charging. I have had the car for 4 years and never seen this charging at other places. The lighting in the garage is the only other thing pulling from that panel and that’s under 300 watts. The house is under 20 years old and has 320 amp service.

6

The nose knows. Yea, if you smelled something burning, you probably did. At a minimum you probably burned up the ballast resistors, and once they are gone, the TVS diode IC would cook. I really don’t have enough information about what happened to speculate any further.

If you send the unit back, and if the damage is limited to localized components, I’ll fix and return for return postage. Send it to:

IoTaWatt, Inc
92 Sewall Rd
Wolfeboro, NH 03894

Please enclose a copy of this message as well as the original order number if you have it.

7

You would get a 10V drop if the combined resistance of the two mains feeder from the street add up to about 0.5 Ohms. That would all depend on wire size and length.

8

Thanks, when I get the time I’ll take the CTs out of the panel so I don’t ruin those as well and send the box your way. :smiley: