Crimping tool recommendations for MC4

[fisherman]

Good Morning,

I haven't been able to come to a conclusion on what MC4 crimper to buyand haven't found much using the search function on the forum on this.

Would anyone have recommendations on what is working for them when crimping MC4?

Thank you

 

[HRTKD]

If you already have a set of ratcheting crimpers, this die may work for it. This is what I use and haven't had any issues with the crimps it makes. All issues have been from me being too low on the learning curve.

Lunar Series Die Set for 4mm Solar Panel Contacts

Application:Multi-Contact ∅4mm Solar Contacts Crimp Size: AWG 14/12/10DIN 2.5/4.0/6.0mm²

eclipsetools.com

 

[B.Babs]

Some good recommendations here

https://marinehowto.com/installing-solar-mc4-terminals/

 

[fisherman]

If you already have a set of ratcheting crimpers, this die may work for it. This is what I use and haven't had any issues with the crimps it makes. All issues have been from me being too low on the learning curve.

Lunar Series Die Set for 4mm Solar Panel Contacts

Application:Multi-Contact ∅4mm Solar Contacts Crimp Size: AWG 14/12/10DIN 2.5/4.0/6.0mm²

eclipsetools.com

Thanks. Unfortunately I don't have a set just yet.

 

[fisherman]

Some good recommendations here

https://marinehowto.com/installing-solar-mc4-terminals/

I will check that out. Thank you

 

[HRTKD]

The biggest issue I had with making MC4 connections was with the operator. I burned through a couple of the crimp terminals making mistakes. Plan it out well and understand what you're doing.

 

[littleharbor2]

I prefer the blue crimper to the red one. I have both and find the blue one easier to use.

 

[littleharbor2]

Color has nothing to do with it. I am referring to the design of the blue one.

 

[RV10flyer]

I prefer the blue crimper to the red one. I have both and find the blue one easier to use.
View attachment 143306View attachment 143307

Yes for the blue handled one. Amazon has it…

IWISS IWS4 Solar Crimping Tools for AWG 14-10(2.5/4/6.0mm2)Solar Panel PV Cables​

 

[Hedges]

Thanks. Unfortunately I don't have a set just yet.

Consider getting one. Some sets have die for many common terminals, so very useful.

I'm not say this one is ideal or not for MC4; sometimes listed crimper/terminal is the thing to do. I've only tried some MC3 so far.
I have one of these, and one of the infamous Harbor Freight hydraulic crimpers (die fitting a terminal is fairly hit or miss, so I suggest researching selection of large lug crimpers carefully.)

 

[SamDeleted]

Pilers ?

 

[HRTKD]

Pilers ?

I had thought about it. But once I saw how the terminals were crimped, I didn't think I could do very well with just pliers. It's not just a flattening of the terminal.

 

[SamDeleted]

I had thought about it. But once I saw how the terminals were crimped, I didn't think I could do very well with just pliers. It's not just a flattening of the terminal.

Certainly fiddly to do

, I think as long as you get a firm crimp it should be electrically sound

 

[RoadTurtle]

I purchased this setup, and very happy with it

https://www.amazon.com/dp/B09M8G3BF1?psc=1&ref=ppx_yo2ov_dt_b_product_details

 

[kundip]

Good Morning,

I haven't been able to come to a conclusion on what MC4 crimper to buyand haven't found much using the search function on the forum on this.

Would anyone have recommendations on what is working for them when crimping MC4?

Thank you

I only use solder.
I dip each end in phosphorcic acid then solder.
Not sure if there is Ranex rust remover in the USA. That has phosphoric acid and works well.
When I crimp a whole bunch one or two usually pull off on testing strongly by hand using pliers. When I soder I can't even pull the lugs off in a vise.

 

[TorC]

Even if using solder for that purpose, I'd still rather crimp first, as you'll get closer to copper to copper connection. Solder is high resistance by comparison.

 

[littleharbor2]

I had thought about it. But once I saw how the terminals were crimped, I didn't think I could do very well with just pliers. It's not just a flattening of the terminal.

The proper dies will crimp onto the wire with a tenacious grip. I doubt you can replicate it with pliers or any other dies. Solder is not needed or even recommended.

 

[Martijn]

Is an MC4 crimper any different from a 'normal' crimper for bare 4-6mm2 lugs/connectors/etc?

 

[SamDeleted]

Is an MC4 crimper any different from a 'normal' crimper for bare 4-6mm2 lugs/connectors/etc?

if you look at them there's 2 arms sticking up like a U shape , unlike normal lugs that are a full circle . You have to fold one side then the other

 

[Martijn]

if you look at them there's 2 arms sticking up like a U shape , unlike normal lugs that are a full circle . You have to fold one side then the other

Here's a photo of the crimper that I have for bare connectors. Looks like the die set @HRTKD mentioned.

 

[littleharbor2]

Here are MC-4 dies. Notice, they fold over both wings of the contact.

 

[RV10flyer]

I only use solder.
I dip each end in phosphorcic acid then solder.
Not sure if there is Ranex rust remover in the USA. That has phosphoric acid and works well.
When I crimp a whole bunch one or two usually pull off on testing strongly by hand using pliers. When I soder I can't even pull the lugs off in a vise.

Oh, that cleans your copper well. The phosphoric acid will weep up the stranded wiring using capillary attraction. In time it will destroy your wiring connections.

 

[kundip]

Oh, that cleans your copper well. The phosphoric acid will weep up the stranded wiring using capillary attraction. In time it will destroy your wiring connections.

I haven't seen bare copper in any twin core solar cable in Australia. It is all tinned along with the lugs.
Tin and tin oxides are known to react with phosphoric acid to produce highly insoluble and relatively inert compounds.
I didn't know your twin core solar cable had bare copper in the USA.
In that case I would probably use phosphoric acid on the tinned lug - prime it with some solder and then solder both together.

 

[Hedges]

Is an MC4 crimper any different from a 'normal' crimper for bare 4-6mm2 lugs/connectors/etc?

It may or may not be somewhat different diameter.
If incorrect size, would either under-crimp or be difficult to crimp to the point of ratchet releasing and leave mashed terminal.

Correct crimps are extremely reliable, used in aerospace, etc.
There seem to be issues with some MC connecters leaking either at the connection (O-ring can fail with re-use) or at the back.

It is important to mate only pairs of connectors that are listed for use together. Either single brand, or mixing brands that were listed together. Many failures and fires are attributed to mix-n-match of seemingly compatible (off?) brands.

 

[scoharri]

Pilers ?

NO!