Capstone Turbine Corporation
Model C65 Hybrid UPS User’s Manual
400027 Rev A (July 2010)
Page
31 of 66
Capstone reserves the right to change or modify, without notice, the design, specifications, and/or contents of this document without
incurring any obligation either with respect to equipment previously sold or in the process of construction.
Emergency Stop
WARNING
Activation of the Emergency Stop function represents an extremely
abnormal event which could be due to building, equipment, or personnel
safety concerns. Thoroughly investigate the reason for issuing an
Emergency Stop command and make sure the cause has been
remedied before attempting to return the system to normal operation.
CAUTION
Repeated use of the optional Emergency Stop function will result in
damage to the MicroTurbine. Use only in emergency situations.
All Capstone MicroTurbines have an emergency stop function called “E-Stop”, which will
immediately disconnect power from the load as well as the incoming utility, shut off fuel
input, and force the turbines into a warmdown. In a warmdown, the turbines do not receive
power from the utility or the external energy storage system, and therefore cannot be
motored to a controlled stop. Instead, the turbines coast to a stop and excess thermal
energy stored in the engine’s recuperator section is released through a compressor
bypass valve. This uncontrolled stop puts abnormal mechanical and thermal stresses on
the system, and can reduce the turbine generator life. Therefore, E-Stop should only be
used as a worst case emergency means to shut the system off.
The E-Stop function is not available as a discrete relay input to the UPS Controller, but
may be directly wired to a building management system for automatic operation in case of
emergency, or may be wired to a manual “Emergency Stop” button. Refer to specific
instructions provided by the building management system integrator or system installer for
the location of any Emergency Stop button or instructions how to activate this function
from the building management system.
After an emergency stop, the power to the MT must be turned off for 30 seconds before a
restart can be attempted. Emergency stops should
NEVER
be used for routine shutdowns.
Also, after an E-Stop, you may want to manually close the external fuel isolation valves to
shut off potential fuel flow into the MT in case there is a fuel leak. The external fuel
isolation valve must be returned to the open position before a restart of the MT is
attempted. An E-Stop operation should be viewed as an extremely abnormal event, and a
thorough investigation as to why the E-Stop command was given should be conducted
before returning the system to normal operation.
Operation Under Fault Conditions
The Hybrid UPS system has been designed to provide high availability of power output even
when a utility source is unavailable, and even if the turbine generator itself cannot operate for
some period of time. A well designed installation will also include n+1 or better redundancy
such that no single unit failure will compromise power to the critical loads. However, there are a
variety of fault conditions that can potentially disrupt power to the critical load. The UPS
Controller continuously monitors the status of the Hybrid UPS systems in its MultiPac, and
provides two hardwired discrete alarm outputs as well as updated fault registers that can be
read using Modbus TCP/IP. A building management system or other external control system
can use this information to take appropriate actions that may mitigate loss of power to the
critical load. Refer to specific instructions provided by the building management system
integrator or system installer for what external actions will be taken and any manual
intervention required with the UPS Controller or Hybrid UPS systems.
