AERCO Electronic Controls System (ECS) - Manual (Page 61)

Electronic Control System (ECS) and Type CXT-E Valve
8. CORRECTIVE MAINTENANCE
VD2: 02/28/14 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 Page 61 of 82
AC-105 OMM-0003_0D
CAUTION
Ensure that the replacement Linkage Assembly, Adapter and
Scale are identical to those removed in the previous steps. Also,
ensure that the Linkage Pin (Figure 8-6) is set to the proper
position for the Control Valve size. Failure to observe this
precaution may result in improper Control Valve operation.
8) Using a new Gasket (29), position the replacement Linkage Assembly on the Valve Top
(21). Secure the Linkage Assembly to the Valve Top using the previously removed Cap
Screws (29).
9) Install the Indicator Plate on the Valve Shaft (16) with the curved end facing upward (Figure
8-4)
10) Attach the Valve Shaft (16) to the Linkage Adapter by rotating the Shaft counterclockwise
(as viewed from above). If the Valve Shaft cannot be turned by hand, use an open-end
wrench to turn the “double-nuts” on the Shaft until it engages the Linkage adapter threads.
Insert the Shaft into the Linkage Adapter until the Hex Nuts (17) are snug against the
Indicator Plate.
11) Press down on the Valve Shaft (16) to compress the Pilot Spring (10) in the Valve Body.
12) Replace the Actuator using steps CM49 through CM56 in the previous paragraph titled
ACTUATOR REPLACEMENT.
13) After performing the Auto Stroke procedure and before applying heat to the system, adjust
the Indicator Scale to the plate. Set the Temperature Controller to the manual mode. Align
the plate while the valve position is at 50% open on the Eurotherm Temperature Controller.
The plate should be at the mid-point of the indicator scale (see Figure 8-4). Tighten the
scale and check the 100% and zero % positions. Readjust as necessary.
14) Go to Section 4, paragraph 4.3 and perform the Initial Start-Up procedure.
8.3 PART 2 - ECS CORRECTIVE MAINTENANCE
The corrective maintenance procedures for the Electronic Control System (ECS) consist of
replacing Control System components and assemblies determined to be faulty in the
TROUBLESHOOTING Section 7 of this manual. These procedures consist of replacing the
complete Control Box, components installed in the Control Box or Control System Sensors and
Safety Devices installed on the Heat Exchanger.
WARNING
TURN OFF THE CONTROL BOX POWER SWITCH AND
DISCONNECT AC POWER PRIOR TO PERFORMING ANY
CORRECTIVE MAINTENANCE PROCEDURES IN THE
FOLLOWING PARAGRAPHS. FAILURE TO OBSERVE THIS
WARNING MAY RESULT IN SERIOUS PERSONAL INJURY.
8.3.1 Control Box Assembly and Components
Corrective maintenance for the Control Box and internally-mounted components consist of
removing and replacing the following items:
• Control Box Assembly
• Temperature Controller
• Over-Temperature Switch
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