[ady1989]

Hello,
 
This question is for anyone who used a Hammond 370 DAX in a build - how hot are they supposed to get? I mounted mine on its side and after an hour and a half of amp use it gets almost too hot to touch. I'd guess around 60* C. Is this normal or am I going to damage something by running it like that? I modified my enclosure top panel for way better ventilation, using it with the top panel closed it must have been around 70-75*C. I know they are designed to stand up but the wires are coming out directly from the bottom.
 
Thanks in advance!

 

[spritzer]

Hammond don't list temp rise at max load but anything above 40°C would be excessive.  Are you sure you are running the transformer within spec and is the primary setup correctly? 

 

[fzman]

if it has multiple primaries and/or secondaries and you need to wire them with proper phase - usually there are dots on the wiring diagram which indicate polarity, either for series or parallel connection - my guess is you have it wired wrong, and the transformer is fighting itself.  disconnect it and do not power it back up until you fix the wiring.

 

[ady1989]

I have it wired as per the Hammond 300 series schematic from their website (below). The 120V AC from the mains goes through a fuse, the power switch and then is wired to the blue and black leads (twisted together) on the transformer. The white and brown wires coming off the 370 DAX are also twisted together and connected to the neutral line for mains (NOT the 3rd fat ground prong, but the 0v line). Is this incorrect?
 

 

[nikongod]

You are supposed to drill holes through the chassis, protect the edges with wiring grommets, and thread the wires through. 
 
It is normal for transformers to warm up. 70c is not really dangerous to the transformer, but I would ideally like it to be cooler. Hammond power transformers tend to run on the warmer side of things. 

 

[ady1989]

I wanted to keep the transformer hidden inside the amp enclosure so I mounted it on its side. I since removed the blue rubber mat to let the case bottom act like a heatsink.
 

 

[nikongod]

  I wanted to keep the transformer hidden inside the amp enclosure.
 

 
Yea, don't do that. 
 
Your chassis is seriously lacking in vent holes for how much stuff you have throwing off heat in there.