Certain faults may require a reset of AC power to DEIMOS. There
are two circuits (orange and blue) and thus two reset boxes.
Access to these boxes is possible through electronics bay 3.
- Rotate DEIMOS to access electronics bay 3. The
electronics bays are located around the large ring-like
structure at the back of the instrument. They are labeled
with numbers and contents. There are three ways to set the
instrument rotator position:
These put the bay on the left and right hand sides of the
instrument, respectively, when viewed from the rear of the
instrument looking toward the telescope.
- Have the observer rotate DEIMOS to an angle of 0°
or 180° from the DEIMOS
- Have the OA rotate DEIMOS to physical drive
angle 90° or -90°.
- Alteratively, you can rotate by putting the DEIMOS
hand paddle in manual mode, turning the mode selector to 0
(fast jog), then using the FWD or REV buttons to turn the
instrument until you can access bay 3.
- Safety first: before removing a cover, put the band brake
on! See figure 1.
- Grab a 5/32 T-handle Allen wrench from the Nasmyth deck
desk on your way to the instrument.
- Remove the access panel shown in Figure
- Note there are some bolts you should not try to
remove. Only remove the ones around the periphery of the
panel which do not have washers underneath them.
- Note these bolts are not captured and you are
standing on grating. Use two hands. If a second person
is available, have them hold their hand under the bolt
while you undo it.
- Figure 3 shows the AC reset switches.
Press the appropriate one to reset the given circuit.
- Re-install the cover. Putting the cover back on is
straightforward other than taking care not to drop the bolts.
- Don't forget when leaving: band brake off, hand paddle in
Figure 1. DEIMOS band brake
Band brake. Push lever down to engage. Pull up to release.
Figure 2. Access Panel
Panel to remove to get to AC power resets.
Figure 3. Reset switches
Electronics bay 3 showing AC resets.