Specifications

NAIROBI OPERATIONAL HUB
UNOPS Building, UN Lane, Off UN Avenue Tel: [phone]
P.O Box 783,Village Market, 00621 E-mail: [e-mail]
Nairobi, Kenya Website: www.unops.org
UNOPS is ISO 9001 certified
vi) Control Functions:
The control system provided shall include a cycle cranking system,
which allows for user selected crank time, rest time, and number of
cycles. Initial settings shall be for 3 cranking periods of 15 seconds
each, with 15 second rest period between cranking periods.
The control system shall include an idle mode control, which
allows the engine to run in idle mode in the RUN position only. In
this mode, the alternator excitation system shall be disabled.
The control system shall include an engine governor control, which
functions to provide steady state frequency regulation as noted
elsewhere in this specification. The governor control shall include
adjustments for gain, damping, and a ramping function to control
engine speed and limit exhaust smoke while the unit is starting.
The governor control shall be suitable for use in paralleling
applications without component changes.
The control system shall include time delay start (adjustable 0-300
seconds) and time delay stop (adjustable 0-600 seconds) functions.
The control system shall include sender failure monitoring logic
for speed sensing, oil pressure, and engine temperature, which is
capable of discriminating between, failed sender or wiring
components, and an actual failure conditions.
The control system shall include all interfaces necessary for proper
operation with the paralleling equipment provided under this
contract. The generator set supplier shall be responsible for
complete compliance to all specification requirements for both the
generator set and the paralleling equipment.
vii) Alternator Control Functions:
The generator set shall include an automatic voltage regulation
system, which is matched, and prototype tested with the governing
system provided. It shall be immune from mal-operation due to
load-induced voltage waveform distortion and provide a pulse
width modulated output to the alternator exciter. The voltage
regulation system shall be equipped with three-phase RMS sensing
and shall control buildup of AC generator voltage to provide a
linear rise and limit overshoot. The system shall include a
torque-matching characteristic, which shall reduce output voltage
in proportion to frequency below a threshold of [58-59] HZ. The
voltage regulator shall include adjustments for gain, damping, and
frequency roll-off. Adjustments shall be broad range, and made
via digital raise-lower switches, with an alpha-numeric LED