How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Kevin Your Own Question
Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3589
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
Type Your Electrical Question Here...
Kevin is online now
A new question is answered every 9 seconds

I am running a system using a 60w/12v solar panel to a 20a/12v

This answer was rated:

I am running a system using a 60w/12v solar panel to a 20a/12v controller. Off of the controller will be a 75ah/12v battery, dc-ac converter 1000w/12vdc-110v ac. From there to a 15a 6 plug power strip that will be feeding 362w of appliances. I would like to know what size wire could be used to accommodate the draw through the system from the panels to the converter and the size of inline fuses to use down to the converter(or inverter?)
Also how do I run wire from the back of the solar panel( MC4 connectors)to the controller. Do I need to purchase the opposite end connectors to attach to my wire or can I strip them back and solder them to the proper gauge electrical wire? name is XXXXX XXXXX I will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!


1) What is the approximate distance from the 60W PV to the battery?

Customer: replied 4 years ago.

Approximately 8 ft. Everything else will be setup around 12-16" from each other.

1) Emily... thanks for the replies


2) Even though the distance is small, I would recommend to run 10 AWG Stranded copper wires for the positive and the negative from the PV's all the way to the battery. In the event you ever want to add future PV's, to the 60W panel, you will be good to go. For an 8 foot run, the voltage drop is very small using 10 AWG. This will provide you with the optimal amperage from the PV to the battery.


3) Under perfect and optimum sun conditions, a 60W PV can generate approximately 4 amps per hour. Rule of thumb in the PV world is approximately 1 amp can be generated for every 15 watts of PV's. 10 AWG Stranded copper is rated at 30 amps, therefore, your 4 amp maximum output is way under the maximum amperage of the 10 AWG wires.


4) Not sure what type of fuses you are planning to use, but as long as they are rated to a minimum of 6 amps, you are good. The extra few amps will allow for any amperage spikes, but doubt if your 60W panel will go higher than 4 to 5 amps on a perfect day.


5) You can either use the mating MC4 connectors or you can splice and solder them together. The benefit of the MC4's will make it easier if you ever had the need to remove the PV from the system or add to it with additional panels. I've installed both on my PV systems and both types of connections work fine. If splicing, just make sure you make a good solder connection and use wire nuts over the finished splices. If you decide to splice and solder, make sure that you install a weatherproof rated splice box with a weatherproof cover. Home Depot and Lowe's both sell these types of boxes in gray PVC and are rated for outside weather conditions.


6) You will also require a weatherproof exterior disconnect switch located as close as possible to the point of entry at the greenhouse. I use non-fusible Air Conditioning disconnect switches that you can purchase at any home improvement or electrical supply store. The cost of the disconnect switch is approximately $7.


7) In addition, your PV metal frame needs to be grounded. You can run a 10 AWG Type THWN rated ground wire inside 1/2" EMT metal conduit or 1/2" gray electrical Schedule 40 PVC conduit and bond this to your ground rod located near your exterior meter socket. If the frame was not provided with a ground screw connection, simply drill a small hole and use a green grounding screw. The equipment ground wire must be installed in some type of conduit in order to preserve the integrity of the ground wire and no physical abuse.


Hope this helps.........If you have any additional questions, let me know and I'll be glad to answer them for you.


Otherwise, don't forget to rate me before you log Off.

The next time you have an electrical question, you can also request for me at:



Customer: replied 4 years ago.

Thank you so much! I plan to use inline blade fuses, is this okay, or should I set up a house type breaker fuse box? Also do I fuse from the battery to the inverter? Can the 10 AWG go from the battery to the inverter? I am very familiar with automotive wiring, but this is new to me!

1) I apologize for my delay Emily, there appears to be a problem with the JA website.


2) Yes, in line fuses are fine for this application since the PV is a very small system. If considering to possibly expand the system in the future, you can always install a fusible disconnect type of switch.


3) No need to fuse from battery to the inverter, but if you want double protection, then is perfectly acceptable. Your Inverter should have a built in fuse protection.


4) Yes, run the 10 AWG all the way from the PV's to the Charge Controller, battery and Inverter.

Kevin and other Electrical Specialists are ready to help you

Emily...... thank you for the excellent service rating as well as the bonus... much appreciated!


If you run into any problems or have any follow-up questions, just reply back to this question and I'll be more than happy to assist you.


In addition to being a licensed electrician, I'm also certified on Solar Panel installs, both off-grid and on-grid applications.


Take care and have a great day...............Thanks................Kevin!

Related Electrical Questions