7 Apr
2007
7 Apr
'07
5:35 p.m.
It's the fan. No doubt about it, it's the fan in the back of the RX02
causing the RL02 to fault.
The fact that there are 2 very difrerent types of fan would possibly
explain why some people have no problems with this arrangement of units
in the rack.
I disconnected the fan and the RL02 no longer faults upon spinup. The moment
I put the molex back on the fan of the RX02 - the RL02 immediately faults.
I decided to take a closer look at this fan in the back of the RX02, so I
took out the 4 screws and pulled off the plastic "wedge shaped" housing. The
fan in there is one of those older odd-looking ones. Not sure how to
describe it. Instead of your "normal" muffin fan where the windings are hard
It's the one I mentioned, I think
to see and they are around the hub... this is the kind
where the fan hub
sits on one side of a large rectangular hunk of iron? Steel? I dunno... big
chunk of heavy metal :)
It's a normal shaded-pole motor. If you look at the stack of laminations
(the 'block of iron' you mention), you'll see 2 thick copper loops round
part of the pole piexces near the rotor. These act as short-circuited
secondary windings (with the normal coil acting as a primary), and cause
a phase shift to the change in magentic fluc on that part of the pole
piece. The result is a rotating magnetic field that causes the rotor to spin.
Actually, the 'muffin fan' motor works in much the same way, but it's a
'Papst motor' with the satore in the middle and a cup-shaped rotor around
it (I asusme you've taken a fan apart sometime...), One of the results of
this is a much lower stray external field (it's screend by the rotor).
I'd try replacing it with a muffin fan. I am pretty sure it's just a normal
115V 60Hz one in your case. I can't remember if 230V RX02s use a 115V or
230V fan, I would have to check the printset, but that doesn't apply to you
anyway.
-tony