User's Manual

Service Menu Parameters
129 Liebert
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iCOM
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different modes of operation. For example, if the fans are operating based on a call for reheat which is
normally 100% fan speed and the reheats are turned Off or no longer needed then the fan speed would
instantly change if this filter is not applied, which may cause instability in the fan speed control. This
filter helps with the transition to avoid overshoot.
S160 Fanspeed Reposition Mode/Delay Decel/—This parameter should be adjusted only by a
factory-trained service trained technician. The fan speed reposition mode / delay is a one-time delay
as the fan speed is requested to change direction. This delay will be applied only when the fan speed is
commanded from an increasing to decreasing state or a decreasing to increasing state. This allows the
fan to hold its current position while the temperature stabilizes.
S161 Max Deceleration Rate—This parameter should be adjusted only by a factory-trained service
technician. Only slows the decreasing of the variable fan speed. The control will use the slower of this
parameter and the fan speed filter.
S162 BMS Backup Fan Setpoint—Selects a temperature setpoint that will be activated in the
event of a BMS time-out. The BMS timer and S163 must be configured to Backup Set for this
parameter to activate. This parameter is adjustable from 41-104°F (5-40°C). The factory default is
73°F (23°C).
S162 BMS Backup Fanspeed—Selects a fixed fan speed percentage that will be activated in the
event of a BMS time-out. The BMS timer and S163 must be configured to BMS Backup Spd for this
parameter to be active. This is adjustable based the unit’s preconfigured low and high limit fan speed
thresholds. The default is 100%.
S163 BMS Backup Fan Operation—Sets the default operation for the fan speed control when a
BMS time-out occurs. Four options are available:
• Disabled (factory default): The fan will continue controlling to the last value written. This could
be either the last Fan Setpoint if controlling the fan by locally installed sensors or it could be the
last value written to Fanspeed STD when fan control is set to manual.
• BMS Backup Spd: Allows the user to program a fixed fan speed percentage setpoint. When the
BMS disconnect occurs, the fan speed will lock to this point. This setting is available when the fan
control sensor is set to Manual.
• Coupled: Allows the fan speed to be controlled by the air temperature setpoint. The fan speed will
follow the call for cooling as described in 3.1.1 - Unit/Fan Control.
• Backup Set: Allows the user to program an alternate fan setpoint for the unit to use when a BMS
disconnect occurs. The setpoint is programmed on S163 or U117 Backup Fan Setpoint. When
active, this setpoint takes the place of S147 Fan Setpoint and is used to establish a new fan
control band.
S164 Allow BMS to change Fanspeed—Enables or disables BMS fan speed control. When this
parameter is disabled, the BMS will not have write capability to this point. The fan control type must
be set to manual before value displayed on this line can be changed to Yes.
S165 BMS is connected to—Sets the BMS fan speed control signal. Two options are available:
• Velocity—Used when fan speed is controlled using a Liebert IntelliSlot
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UNITY-DP
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and legacy
L-Cards (IPBML & 485L).
• Ana In 1 - 4—This setting is used when the fan speed command is provided using a hard-wired
connection into one of the control boards available analog inputs. After the user has selected an
available input, a new right hand parameter will populate allowing the user to select the analog
input signal type. Input signal selections include 0-5 VDC, 0-10VDC and 4-20mA.
S166 High Temp Limit Approach—Sets the sensor to be used to increase the fanspeed value above
the fanspeed setpoint STD to the value set in the Analog Out high limit. This parameter is selectable
from Disabled, Supply and Return. The default is Return.
S16A High Temp Limit Approach At—Sets the temperature differential below the high supply
and high return temperature limit where the fan speed would increase from fanspeed setpoint STD to
fanspeed MAX. This parameter is selectable from 0 - 10°F. The default is 2°F.
S16B FC / AirEco Ramp Up w/CFC—Sets the selection to decouple the fan output from the call for
cooling. This parameter is selectable from No or Yes. The factory default is No.