Datakom D-500 MK2 - Parallel Operation with Mains; Peak Lopping Feature

D-500 MK2 User Manual Firmware V-6.3
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The Peak Lopping feature consists on the use of the genset system as a backup to the mains, in cases
where the mains power rating is insufficient to supply the load.
When peak lopping is enabled and the unit is in AUTO mode, if mains power exceeds the parameter
Peak Lopping Start Power during Peak Lopping Start /Stop Delay, then the genset system will start
and enter in parallel with the mains. As the mains power limit is not exceeded it will not supply power to
the load.
When the total load power exceeds the parameter Peak Lopping Maximum Mains Power the unit will
allow the mains to deliver only Peak Lopping Maximum Mains Power to the load. The exceeding
quantity will be supplied by the genset system.
When the total load power falls below the parameter Peak Lopping Stop Power during peak lopping
start/stop delay Peak Lopping Start /Stop Delay the load contactor will release and the unit swill start
the stop sequence.
The parameter Peak Lopping Stop Power should be less than the parameter Peak Lopping Start
Power in order to prevent unstable operation (genset starts and stops repeatedly).
The unit offers a comprehensive set of protection functions to detect quickly a mains failure during parallel
operation with mains. The protections are enabled after the timeout defined by the parameter Parallel
Check Delay. These protections will be explained with more detail in the chapter G59 PROTECTIONS.
If a mains failure occurs during parallel operation with mains, the mains contactor will immediately de-
energize, a general Parallel Mains Fail warning and a specific protection function warning will be
generated. The load will be supplied by the multi genset system without interruption. When mains is
restored again, the D700 will synchronize the genset system with the mains and resume to parallel
operation.
The D700 has a set of programmable parameters to define the Peak Lopping operation. All parameters
used in Uninterrupted Transfer and Soft transfer are also used in Peak Lopping. Additional parameters
are:
Parameter Definition
Description
Peak Lopping Enable
This parameter enables/disables the Peak Lopping operation.
Peak Lopping Maximum
Mains Power
This is maximum active power that the mains may deliver.
Peak Lopping Start Power
This is the mains active power limit for the start of the multi genset
system.
Peak Lopping Stop Power
This is the total load active power for the stop of the multi genset system.
Peak Lopping Start /Stop
Delay
This is the delay time for starting/stopping of the multi genset system.
The peak lopping may be disabled momentarily with an external signal. In order to achieve this, a digital
input should be programmed as Disable Peak Lopping function input. More information about input
programming is found in the PROGRAMMING chapter.
The peak lopping application is only possible with slowly varying
loads.
31.1. PEAK LOPPING
31. PARALLEL OPERATION WITH MAINS