Emerson Liebert CRV 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 C R 0 2 0 R A 1 C 7 S D 1 8 1 1 E L 1 0 P A - Manual (Page 110)

Operation in Teamwork Mode
Liebert ® CRV ™ 102
11.4.5 Standby—Rotation
Typical Standby (Lead/Lag) Function
This function can be performed in any teamwork mode, including NO Teamwork.
One or more units can be defined to be Standby; the normal status of standby units is Standby Off
(fan off).
In case one regular unit has an alarm that is defined (to be defined in the alarm configuration), to
switch on a standby unit, the faulty unit will switch off and the standby unit will switch on.
If the next unit has an alarm, the next standby unit will be started. If no more standby units are
available, the unit with a non-critical alarm that permits unit operation will be switched on again
(water detection, fan alarm, fire alarm etc. will not permit unit restarting).
The standby function can be rotated daily (setting the time), weekly (setting the day of the week and
time) or monthly (setting the first weekday of the month and time).
The rotation is performed with a selectable number of units: if 1 is selected, to standby rotates from
1-2 to 2-3 in a 4 units configuration with two standby units, and rotates from 1-2 to 3-4 in the same
configuration, when the rotation parameter is set to 2.
Standby and Cascade
Cascade is possible in Teamwork Mode 1 only.
Standby units will start if an alarm occurs in one of the operational units. If the standby units are
cascaded, they will also start and work with the regular operational units if the temperature or
humidity cannot be controlled by the operational units; before a high or low temperature / humidity
condition occurs. Cascaded units are switched off again as soon as the temperature / humidity returns
back to normal.
The master unit defines its proportional band according to the number of available units (see
11.4.3 Teamwork Mode 1).
When a standby unit receives a request for full heating or cooling from the master unit, it will
respond to the request after its control delay.
NOTE
Before entering standby mode, units will operate the fan only for 3 minutes to cool the electrical
heaters, remove steam from the unit, etc.
NOTE
Cascaded units are not included in the calculation of the average temperature / humidity.