You don't need an accessory fan when the shelter is well ventilated so cooler air can come in near the floor and heat can escape near the roof or upper part of the cabinet - natural air flow & ventilation. It is in the more airtight, sound deadening cabinets were accessory fan become very important to cool the heat producing compressor. I've seen some cabinets get hot enough to melt the compressor's cord coating and compressor 'died'.
If it was melting the wiring, they screwed up really bad in wiring in it the first place!
At least, get a Licensed Electrician with a VALID LICENSE to hook it up.
Sheesh!!!
