DAS Air Plenum Removal and Installation

Prerequisites

Overview

Remove Air plenum:

Always turn OFF the HVDC before the 12VAC. Turning OFF 120VAC power before HVDC power can result in equipment damage.

Remove gantry covers, shut OFF power, and lock the gantry in position Accessing the DAS Assembly.
Unscrew four (4) screws, and remove the EMI shielding plate if it exists on the system (not all systems have this plate). See Figure 1.

Figure 1. DAS shielding plate
Disconnect Fan AC power at Connector J22.
Set air baffles on either end of the duct to the “Removal Position” (see Figure 2):
1. Loosen knurl nuts
2. Slide baffle into position
3. Hand tighten knurl nuts
Figure 2. DAS Air Plenum: Baffle & Mounting Bolts
Remove four (4) mounting bolts (2 at each end). See Figure 2.
Carefully slide the plenum towards the front, without catching wires or Detector flexes.
Set the plenum aside, on a clean surface.
Continue with replacement procedures that required removal of this plenum.

Ensure that baffles are secured in “REMOVAL POSITION”.

Figure 3. DAS Air Plenum Installation
Lift plenum into place, and align guide holes with guide pins.
Slide plenum onto guide pins.
Fasten plenum securely into place, using the four (4) mounting bolts and four lock washers. Torque to the following values depending on which system type you have.

Table 3. 4/8 Slice Systems
7.9 N-m 5.8 lb-ft 70 lb-in 80.5 kg-cm

Table 4. 16 Slice Systems
38.4 N-m 28.3 lb-ft 340 lb-in 391.4 kg-cm
Return baffles to the “OPERATING POSITION”.
Install the EMI shielding plate using four (4) screws, lock washers, and flat washers. Torque to values shown in Table 5.

Table 5. EMI shield Torque
7.9 N-m 5.8 lb-ft 70 lb-in 80.5 kg-cm
Connect Fan AC power at Connector J22.
Remove rotational lock, restore power and reassemble gantry covers.

No finalization steps.