Connections - Danfoss VLT Series Operating Instructions Manual

1 Extended and Advanced Cascade Controller
Option
27-54 Alternate at Time of Day
Option:
1
[0] * Disabled
[1] Time of Day
27-55 Alternation Predefined Time
Range:
1:00* [00:00 – 23:59]
27-56 Alternate Capacity is <
Range:
0% (Off)* [0% (Off) – 100%]
27-58 Run Next Pump Delay
Range:
0.1s* [0.1s – 5s]

1.8.8 Connections, 27-7*

Parameters for configuring relay connections.
27-70 Relay
Option:
Standard Relay
34
Function:
Alternate at Time of Day allows selecting a specific time of day for alternating pumps. The time is
set in parameter 27-55. Alternation at Time of Day requires the real time clock to be set.
Function:
Alternation Predefined Time is the time of day for pump alternation. This parameter is only available
if parameter 27-54 is set to Time of Day.
Function:
Alternate Capacity is < requires the lead pump to be operating below this capacity before time based
alternation will be allowed to take place. This feature ensures that alternation only takes place when
the pump is running below a speed where interruption in operation will not affect the process. This
minimizes the system disturbance caused by alternations. The value is entered as a % of the ca-
pacity of pump 1. Alternate Capacity is < operation may be disabled by setting this parameter to
0%.
Function:
Run Next Pump Delay is a delay between stopping the current lead pump and starting the next lead
pump when alternating lead pumps. This provides time for the contactors to switch while both
pumps are stopped.
Function:
P27-70 is an array parameter used to setup the function of the option relays. Depending on which
option is installed only the available relays will be visible. If Extended Cascade controller is installed,
relay 10-12 will be visible. If Advanced Cascade controller is installed relay 13-20 will be visible. In
both cases, the standard relays (Relay1 and Relay2) will be accessible as well as the relays in the
B-option MCB-105 (if that option is installed in combination with advanced cascade).
To setup the function of each relay, choose the specific relays and then choose the function. If the
function option: Standard Relay is choosen, the relay can be used as general purpose relay and the
wanted function can then be setup in parameter P5-4*.
®
MI.38.C3.02 - VLT is a registered Danfoss trademark
®
VLT Operating Instructions