Discussion related to commuter rail and rapid transit operations in the Chicago area including the South Shore Line, Metra Rail, and Chicago Transit Authority.

Moderators: JamesT4, metraRI

  by Tadman
I'm looking at my copy of the second Morning Sun CSS book and it discusses motor 900's retirement in 1960. The book states that the main fuse blew which precipitated the retirement. What is this main fuse, and is it really that big/expensive to cause the retirement of a motor?

On the other hand, the CSS was at its high point for motors in 1960, having all three 800's, most 700's, and quite a lot of the original and ex-IC steeplecabs in operation at one time. It's not like they needed power.
  by byte
"Main fuse" is probably a misprint. What's more likely is the main transformer blew, which as I'm sure many know happens to Amtrak's AEM-7s on a somewhat recurring basis and isn't pretty when it happens.
  by Milwaukee_F40C
Fuses are designed to blow and be easily replaceable to prevent further damage. Maybe it was a problem where the "main fuse" was being used too much, causing the unit to fail frequently on the road, and it wasn't worth the trouble to find a grounded wire or short circuit or fried out device in the miles of electrical equipment. Older diesel locomotives are often retired for similar reasons when they basically become useless because the traction motors can't get full power load. Fixing stuff like that could involve checking a lot of circuits before the problem is found.