I have a hydroponics Arduino setup where I run a submersible water pump that runs on 5.4V, 60 Watts. I have an aviation connector that I want to use to hook the pump up to my pelican box. The problem is that the connector is rated at 5V. Will this produce too much heat and present a fire risk? What problems will I encounter if I use a connector that isn’t rated at the full voltage of the component?
Edit - it’s a 12V system. I mistakenly said 5.4V when it’s 5.4A. Poor typo on my part. The connector is rated at 5A.
In a clean dry environment I would not worry, much, but I heard pump, that means fluids. I would worry about corrosion, the connector will probably fail over time.
Certainly time and environmental effects are the bane of connectors.
To make the connector you have last the longest I would suggest four things:
If possible replace the wires with 16 or perhaps 14 gauge wires. The wire size is overkill for your circuit but believe it or not, the heavier wire will draw heat from the connector pins. The heavy wire need not be more that 6" long on each side of the connector.
Secure the connector so it absolutely doesn't move this is especially true for the input and output wires. Reason is that movement of the contacts causes "fretting" corrosion, not good for long term reliability
If the connector has 3 pins and is in line, I would suggest they be wired Gnd-Gnd-Plus. The natural inclination is to put the plus in the middle with grounds on both sides. This is not a good configuration as it doesn't provide the best thermal path for the middle pin.
If you are paralleling two pins, don't jumper them at the pin, but some feet down the cable. The goal is to make sure the connector pins share the current. In actuality this recommendation is not so beneficial. If it is really needed you already are at a risky operating current.