Connecting pv mc4 live in daytime

[Jason flores]

I'm some what confused I was told don't plug my series panels in live .
I have 10 500w 37v 15a panels I'm building in daylight when all are together that's 370 dc Volts I'm told not to plug the mc4 male / female together it could kill me .
I would have to wait for dark to plug in the end of series + - or several blankets ?
What if I rubber gloved ?
Or ?

Thanks in advance

 

[millsan1]

blankets, tarps, whatever, and a multimeter are your friend.

 

[yodamota]

I definetly leave the "connecting the whole system together" up to the circuit breaker.

 

[gotbeans]

I wired mine in the day so I could see.. I wouldn't do it in rain though
Then I connected the array to my wire that runs to my on/off switch
then I went and turned the switch on

You can definitely get some rubber gloves. There are tons of different electrician gloves

https://www.amazon.com/Electrical-Insulated-Electrician-Protective-Insulating/dp/B07S878KNX

https://www.amazon.com/National-Safety-Apparel-Insulating-DWH11010/dp/B00Y2RBYOS/

etc

In the middle of the night my array still has 120 volts (according to the inverter) on an average night. Not sure if it's from town lights or moon or what. I get up to 200volts on full moon.. So I wouldn't say night is that much safer, at least you can see during the day.
It's only a few milliamps to kill you if it goes to the right place, since the voltage is always so high it'll always go through the human body

 

[42OhmsPA]

Make sure you aren't running any loads or trying to charge and you'll be fine.
Do not attempt to connect or disconnect under any load unless you want issues and potential injuries.
Wear appropriate PPE if desired.

 

[Hedges]

MC4 connectors are touch-safe.
You don't want to disconnect them with current flowing, might draw an arc that could bite you.

You can connect them together and to a circuit that has switch/breaker open so no current flow. Then when circuit closed, they will deliver Isc into capacitors and charge it up.

If connecting PV strings in parallel, or connecting to a wire that disappears into equipment, I like to check voltage with DMM. If open circuit it may read Voc (480V in my case) momentarily, but then decays toward zero as wire capacitance charges up. If DMM continues to read voltage, don't connect because current will flow.

If inserting DMM test leads into MC4 connectors, be very deliberate about not coming into contact with the exposed test leads. One of these days I'll get some MC4/Banana cables.

Also, check voltage and polarity before closing breakers/switches, make sure it is correct for the equipment.

 

[Jason flores]

Make sure you aren't running any loads or trying to charge and you'll be fine.
Do not attempt to connect or disconnect under any load unless you want issues and potential injuries.
Wear appropriate PPE if desired.

So at the end of my series array where I have one + and one - I want to plug into a on/off disconnect I was told as soon as I hook up all the series connections together the lines are hot with 370v ?? After disconnect switch I have a 50ft run to another pv disconnect right before inverter .

 

[gotbeans]

So at the end of my series array where I have one + and one - I want to plug into a on/off disconnect I was told as soon as I hook up all the series connections together the lines are hot with 370v ?? After disconnect switch I have a 50ft run to another pv disconnect right before inverter .

Yea consider the lines of solar panels always hot.. It's hard for me and some others but you must resist licking them
You have two switches, one at your array itself and one near the inverter? Just make sure both are off, and connect your stuff (triple check make sure the polarity is correct)
then turn them on

 

[42OhmsPA]

If inserting DMM test leads into MC4 connectors, be very deliberate about not coming into contact with the exposed test leads. One of these days I'll get some MC4/Banana cables.

Also, check voltage and polarity before closing breakers/switches, make sure it is correct for the equipment.

I want a set too. DIY or buy? ?
Fluke Pomona Solar MC4 to 4mm Test Lead Set https://a.co/d/jepUTCO

 

[stevenforti]

I was wondering this same thing.

So it's okay to just wire up the MC4s in daylight without covering the panels? I was on the market for some pretty big tarps. 10 of them as I purchased 10 panels

 

[Hedges]

Covering panels, working in evening or night, tilting them away from the sun, all serve to reduce current low enough to not burn contacts.
But don't trust it to make the circuit safe/non-hazardous/extra-low-voltage. Never touch the conductors.

It is fine to mate and unmate MC4 connectors in full sun. Just make sure no current is flowing.

 

[Hedges]

I want a set too. DIY or buy? ?
Fluke Pomona Solar MC4 to 4mm Test Lead Set https://a.co/d/jepUTCO

Whatever is available in name-brand quality for a premium price, someone else will undercut.

Amazon.com

 

[gotbeans]

I was wondering this same thing.

So it's okay to just wire up the MC4s in daylight without covering the panels? I was on the market for some pretty big tarps. 10 of them as I purchased 10 panels

IMO buy some of the $20 gloves instead of tarps. The MC4 connectors are so far in they're pretty safe though even without

Whatever is available in name-brand quality for a premium price, someone else will undercut.

Amazon.com

ty china. WJSTN very reputable, known name, one of my favorite companies. Totally not random letters
I actually have their gold plated banana plugs for audio which is funny because there's like 500 other random named companies with those too

 

[Hedges]

What gloves are you thinking of?

Need leather protectors too. Otherwise, after one day's use, you're supposed to send them in for retest.

 

[42OhmsPA]

So at the end of my series array where I have one + and one - I want to plug into a on/off disconnect

Correct

I was told as soon as I hook up all the series connections together the lines are hot with 370v ??

Correct.

After disconnect switch I have a 50ft run to another pv disconnect right before inverter .

I had ~30'.
I wired all panels up, 2 6s strings, and paralleled them at the combiner box. From there I wired them into the disconnect. I then metered for correct polarity and voltage, turned the disconnect off and ran them back to the house.

Somehow I never took finished photo...

 

[gotbeans]

What gloves are you thinking of?

Need leather protectors too. Otherwise, after one day's use, you're supposed to send them in for retest.

The random ones I linked above
not saying to touch any wire but if he's really concerned they're available

 

[stevenforti]

where's the link to the gloves?

 

[Hedges]

OK, but you need one of these on the outside to prevent damage.

https://www.amazon.com/Magid-Master-Linesman-Voltage-Protector/dp/B075D9GLZL

Amazon.com

A nicked rubber glove wouldn't do much for you.

 

[Hedges]

where's the link to the gloves?

Connecting pv mc4 live in daytime

I'm some what confused I was told don't plug my series panels in live . I have 10 500w 37v 15a panels I'm building in daylight when all are together that's 370 dc Volts I'm told not to plug the mc4 male / female together it could kill me . I would have to wait for dark to plug in the end of...

diysolarforum.com

 

[42OhmsPA]

IMO buy some of the $20 gloves instead of tarps. The MC4 connectors are so far in they're pretty safe though even without.

I was overly nervous my first time since I've never worked directly with voltage that high, I'm around it everyday, I was going to borrow gloves from a friend who's a lineman.
I ended up wearing a pair of leather gloves and using common sense and everything was fine. My 2nd array was bare hands.

 

[gotbeans]

OK, but you need one of these on the outside to prevent damage.

https://www.amazon.com/Magid-Master-Linesman-Voltage-Protector/dp/B075D9GLZL

Amazon.com

A nicked rubber glove wouldn't do much for you.

good tip, amazon seems to recommend you get a pair with them too

I was overly nervous my first time since I've never worked directly with voltage that high, I'm around it everyday, I was going to borrow gloves from a friend who's a lineman.
I ended up wearing a pair of leather gloves and using common sense and everything was fine. My 2nd array was bare hands.

probably both were "basically" bare. I think anything over 100v will go straight through the leather gloves hehe

just tested with my transformer, with AC at least 62 volts went through them lol

 

[42OhmsPA]

Whatever is available in name-brand quality for a premium price, someone else will undercut.

Amazon.com

I saw them but the reviews aren't reassuring. I feel like I could buy a set of Klein test leads, https://a.co/d/ggHokkz cut the ends off and crimp some MC4 connectors on with the tabs cut off of the housing for a quality diy set.

 

[gotbeans]

I saw them but the reviews aren't reassuring. I feel like I could buy a set of Klein test leads, https://a.co/d/ggHokkz cut the ends off and crimp some MC4 connectors on with the tabs cut off of the housing for a quality diy set.

Why do you want MC4 on multimeter? they are pain in the ass to remove or is that why you want them? I guess you can sand off the clips so it's easier to plug in and out
I'd go your route though and just wire some leads up to the

Amazon.com

 

[stevenforti]

Connecting pv mc4 live in daytime

I'm some what confused I was told don't plug my series panels in live . I have 10 500w 37v 15a panels I'm building in daylight when all are together that's 370 dc Volts I'm told not to plug the mc4 male / female together it could kill me . I would have to wait for dark to plug in the end of...

diysolarforum.com

I Have pretty much the same. 10 535 watt solar panels I'm planning on putting in series

 

[Hedges]

One thing to look for in shrouded banana plugs is plastic tip on conductors.
I've been using boxes of banana I get cheap through eBay ($40 for 70 connectors), but there is exposed metal so close to the surface I could touch if I pushed my finger on it.

Observe plastic tip on these contacts: