Installation and Maintenance Manual

Controls Interface
RLC-SVX09H-EN 165
If this setting is set to “None”, fan control shall be per the
full speed fixed speed fan tables with each circuit applying
the Fan Deck Arrangement configuration selected below.
If this setting is “Two Speed Fan” (TSPD), fan control shall
provide for the first fan to be a two speed fan and control
and the first two relays of the quad relay shall be used for
low and high speed control of that fan. TheTwo–speed fan
operation, assumes the use of fans and contactors
designed for Wye (low speed) and Delta (high speed)
motor connections and the ratio of the low to high speed
cfm is approximately 80%. ForTwo-Speed fan
configurations, low to high and high to low speed
transitions are subject to a 5 second delay with neither the
low speed nor the high speed contacts being energized.
The low speed contact generally refers to relay 1 and the
high speed contact generally refers to relay 2.
Note: When selecting two speed fan control for the low
ambient option, only the Fan Deck Arrangements
with an “H” in the 2nd position of the fan grouping
definition are supported.
If this setting is “Variable Speed Fan with Analog
Interface”VARA, the fan control shall operate fixed speed
fans as well as a single inverter driven fan, and the controls
include the enabling and speed command signals to this
variable speed inverter.The inverter shall have an analog
interface and fault feedback and be similar to the DanFoss
TR1 2800 series inverter.
For variable speed fan decks, the first relay controls the
variable frequency drive, through an enable/disable input
of the inverter.The Variable speed fan option supports an
inverter fault input to monitor the fault state of the inverter.
An inverter fault or other inverter-related diagnostic
causes the fan control to de-energize the inverter relay,
command a zero percent speed via the analog speed
command interface, and reverts to a special fixed-speed
fan control mode.
In normal operation (no inverter diagnostics), the inverter
is not commanded to zero-speed unless all other fans are
commanded off. During normal operation, a minimum
inverter speed command is enforced to prevent counter-
rotation of the inverter driven fan. Counter-rotation can
reduce fan deck capacity and negatively affect reliability of
inverters and its fans.
Variable Speed Analog Fans
Each independently controlled variable speed fan has
three I/O points:
• A fan deck relay controls the inverter run/stop
command state. (Inverter power is continuously
applied and not controlled by a contactor.)
• A 0-10 Volt analog output commands the variable
frequency drive’s speed.
Output Voltage [V] = Desired VFD Speed [%] /10, with a
minimum Desired VFD Speed of 7% (0.7V).
To send a reset command, 0% (0.0V) is sent.
• A binary input senses inverter faults.
The Fan Inverter Fault LLID binary input expects to see and
open-circuit (i.e open dry contact) on its respective input
terminals when the inverter is de-energized or when an
inverter fault is present.
The Fan Inverter Fault LLID binary input expects to see a
closed circuit (i.e. closed dry contact) when the inverter is
energized and no faults are active.
The inverter fault diagnostic is not activated until 5
seconds after the inverter Run/Stop command relay is
energized.
Fan Deck Arrangement Circuit 1
Note: Present if A/C Fan Control (ACFC) = Integral Fan
Control (INT)
This setting defines the wiring of the four fan relays
outputs of the Fan Control Relay LLID for the respective
circuit (circuit 2’s setting is shown above). It indicates the
fan grouping in terms of how many fans each particular
relay is expected to control. The numbers in parentheses
refer to the number of fans controlled by each of the 4
relays in order (lowest terminal number designators first).
“H” means reserved for high speed of 2 speed fan, if
applicable - if no two-speed fan selected in LAFC, then “H”
implies no fans wired to this relay.
Figure 70. Fan deck arrangement