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.
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