Topic ID: id_15460431
Version: 3.0
Date: Jan 20, 2020 8:32:33 PM

Detector Routing Board and Thermostat Replacement

Prerequisites

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Standard tool kit	AR	-	-	-
19mm socket, 2.5mm and 4mm hex drive bits	1	-	-	-
10mm hex bit socket drive - supplied with system	1	-	-	-
12mm long hex driver	1	-	supplied with system	-
VCT lift arm assembly	1 set	-	supplied with system	-
VCT chain hoist - order from Tool Depot (Chain hoist with roller arm/hook instead of 2 hooks will not work)	1	-	5149069	-
VCT Detector Lift Hook - order from Tool Depot	1	-	5142366	-
Large Torque wrench for gantry balance - Order from Tool Depot	1	-	46-268521G1	-

Table 5. Safety

danger

CRUSH HAZARD.
UNEXPECTED GANTRY ROTATION CAN CAUSE SERIOUS INJURY.
Never service the gantry with the axial drive enabled. Use the gantry rotation lock to lock out gantry rotation. See safety menu of Service Document gui for appropriate procedures.

Table 6. Required conditions
Condition	Reference	Effectivity
This procedure references the detector replacement procedure. Remove all gantry covers per that procedure.	-	-

Overview

This procedure describes how to replace the Detector Thermostats/Routing board assemblies on either end of the detector. Removing the detector from the gantry allows easy access to the thermostats although it is possible to remove the routing board assemblies with the detector in place but much more difficult.

1 Gantry Preparation

Procedure

Use the VCT Detector replacement procedure including gantry cover removal steps to pull the detector away from the gantry for easy access to the routing boards.

2 Routing board/Thermistor replacement

The Low channel Routing board is on the 48V Power supply side of the detector on the end of the detector rail. High channel routing board is on the end by the 107 weight stack.

Procedure

Remove the 4 screws holding the cover to the routing board standoffs.
Remove the 4 studs to remove the board from the detector. Then remove the 2 screws of the thermostat under the board and remove the assembly.

3 Routing board/Thermistor installation

Procedure

Position the thermostat and install the 2 screws to fasten the thermostat to the detector rail.
Position the board and install the 4 stud to fasten the board to the studs on the detector rail.
Install the cover.
Finish reconnecting all cabling and then reinstall the Detector per the VCT detector replacement procedure Installation process including cover installation steps.

4 Finalization

Procedure

Allow the detector to warm up while monitoring the detector temps to make sure all 3 zones are coming up to temperature using DAStools Aux channel test to report current rail temperatures. The detector may take up to 45 minutes to come up to temperature. Perform any tests required to confirm original problem has been resolved.
Perform IQ checks per the Detector Replacement procedure. If any IQ issues are identified perform a full Detailed calibration and Fastcal.