Field Wiring; Field Output Signals; Remote Alarm Output; Fan Operation Output - Daikin MicroTech II Installation And Maintenance Manual

Field Wiring

Field Wiring
Below are descriptions of the various options and features that
may require field wiring to the MicroTech II controller. Refer
to the job plans and specifications and the as-built wiring
schematics. For a typical set of wiring schematics, refer to
"Typical Wiring Diagrams" on page 34.
For more information on the electrical installation, refer to
"Field Control Wiring" in the "Electrical Installation" section
of the applicable unit installation manual (see Table 2 on
page 1).

Field Output Signals

The following output signals may be available for field
connections to a suitable device:
• Remote Alarm Output (MCB-BO4)
• Fan Operation Output (MCB-BO3)
• VAV Box Output (MCB-BO12)
• Generic condensing unit staged cooling outputs
(GCB1–BO1 through GCB1–BO9)
The Remote Alarm Output and Fan Operation Output are
available on all units. The VAV Box Output is available only
on VAV units. The optional staged cooling outputs are
available only on RDS and RAH units interfaced to a
field-supplied condensing unit.

Remote Alarm Output

The Remote Alarm Output (MCB-B04) supplies 24 VAC to
terminal 115 on the field terminal block (TB2) when the output
is on. To use this signal, wire the coil of a field supplied and
installed 24 VAC pilot relay across terminals 115 and 117 on
TB2. When this output is on, 24 VAC is supplied from the T3
control transformer through output relay MCB-B04 to energize
the field relay. Refer to the as-built wiring diagrams.
The total VA of all field-mounted relays cannot exceed 15
VA, and they must have a 24 VAC Class 2 coil. Other power
can cause unit malfunction.
The action of this output depends on the setup of each of the
possible alarms. The output is on continuously (field relay
energized) when there are no active alarms within the unit
controller. Each alarm is then configured to cause the output to
turn off, blink on and off rapidly, blink on and off slowly, or
remain on (no alarm indication). For details regarding how to
use the keypad to configure these alarms, refer to the "Alarm
Monitoring" section of the applicable operation manual (see
Table 1 on page 1).
12
CAUTION

Fan Operation Output

The Fan Operation Output (MCB-B03) supplies 24 VAC to
terminal 116 on the field terminal block (TB2) when the output
is on. To use this signal, the coil of a field supplied and
installed 24 VAC pilot relay must be wired across terminals
116 and 117 on TB2. When the output is energized, 24 VAC is
supplied from the T3 control transformer through output relay
MCB-B03 to energize the field relay. Refer to the as-built
wiring diagrams.
The total VA of all field-mounted relays cannot exceed 15 VA,
and they must have a 24 VAC Class 2 coil. Other power can
cause unit malfunction.
The Fan Operation Output (MCB-BO3) can be used to control
field equipment that depends on fan operation (field installed
isolation dampers, VAV boxes, etc.) This output is turned on at
the beginning of the Startup operating state and remains on
during fan operation. The fans remain off during the Startup
operating state allowing time for equipment such as isolation
dampers to open prior to the starting of the fan. The duration of
the Startup operating state is adjustable by setting the Start
Init= parameter in the Timer Settings menu on the keypad.
When the unit is shut off this output remains on for 30 seconds
after the airflow switch stops sensing airflow. This output is on
whenever the airflow switch senses airflow.
Note – If the DF CapCtrl= parameter in the Unit Configuration
menu of the keypad is set to "Position," the output turns
off three minutes after the unit shuts off and remains off
until the unit is restarted. For more details regarding the
sequence of this output, refer to the applicable operation
manual (see Table 1 on page 1).
CAUTION
Daikin IM 696-4