Honeywell CENTRA LINE MERLIN NX Series - Service Button; Pressing Service Button during Power-Up; Pressing Service Button during Normal Operation; Mounting

MERLIN NX IP AND MST/TP VAV CONTROLLER - INSTALLATION INSTRUCTIONS
EN1Z-1076GE51 R0722 8
Service Button
Fig. 5. Service Button
The service button is used to trigger dedicated events. It is
important to distinguish different controller behaviors
elicited depending upon whether the service button is
pressed when the controller is powering up or when it is in
normal operation.
See the following dedicated events:
Pressing Service Button during Power-Up
If the service pin is pressed and the controller is switched
on (while the service pin is still pressed), a reset to factory
delivery is performed.
• The application is cleared from the controller.
• The MAC address will be set to 0xFF, meaning that the
controller will now search for a new mac address (Auto-
MAC will be automatically triggered after controller
power-up).
• The maxMaster setting will revert to its default value
(See “AutoMAC limitation:” on page 24. for default
values).
• The Max info frames will revert to 10.
• The device instance will revert to its default of 4194302.
• The device name will revert to CLMEVA[ModelName].
• The values of Auto MAC, Min MAC and Max MAC will be
reset to default (See “AutoMAC limitation:” on page 24.
for default values).
• The Modbus, Ethernet, and BLE settings will revert to
their factory settings. The user settings for Modbus and
BLE will be erased, the IP address will be reset to
default, and the device will enter DHCP IP configuration.
Pressing Service Button during Normal
Operation
During normal operation of the controller, a short press (< 1
sec) of the Service Button will cause a Service Pin
Message (BACnet WhoAmI as a Private Transfer
(SerialNo. = 130)) to be sent. This can be used in tools to
verify devices (Tool can do a ranking of multiple service pin
messages received).
MOUNTING
To mount the MERLIN NX IP and MSTP VAV controllers,
refer to the mounting instructions provided with the
controller.
Before mounting the controller on the damper shaft, review
the power, inputs, and output specifications. See
“Specifications” on page 4.
Hardware driven by the analog current outputs must have a
maximum resistance of 550 Ohms.
NOTE:
Avoid mounting in areas where acid fumes or other
deteriorating vapors can harm the metal parts of the
controller or in areas where escaping gas or other
explosive vapors are present.
Before Mounting Actuator onto the
Damper Shaft
MERLIN NX IP and MSTP VAV controller include a direct-
coupled actuator with Declutch mechanism, which is
shipped hard-wired to the controller.
1. Determine the direction in which the damper shaft
rotates to open the damper. Typically, there is an
etched line on the end of the damper shaft that indi-
cates the position of the damper.
Service
Button