Samlexpower Evolution EVO-2212 Owner's Manual page 63

SECTIOn 4 |
- When the unit powers up, it starts in Inverting Mode first. The output voltage ramps up
gradually from around 48 VAC to 120 VAC in around 200 ms. This reduces otherwise very
high starting inrush current drawn by AC loads like Switched Mode Power Supplies (SMPS)
and motor driven loads like fans, pumps, compressors etc. This will result in lower motor
inrush current (which typically can be up to 650% of the full load current of the motor),
which means lesser mechanical stresses, wear and tear and increased lifetime of the motor,
coupling and fan. Additionally, the impact on the load side components is greatly reduced,
meaning less likelihood of causing problematic voltage drops during starting.
Power Surge – up to 300%:
- The inverter is able to deliver very high surge power / current of up to 300% for 1 ms followed
by 200% for 100 ms. This range of high instantaneous power is delivered at the rated voltage
and hence, it is able to provide very high starting torque for difficult motor driven loads like
compressors and pumps that require higher Locked rotor Current during startup.
- If the power drawn by the load exceeds the above surge ratings, the inverter protects
itself by limiting the load current to 300% / 200% which results in reduction of
output voltage and consequent reduction in load current. The output voltage recovers
automatically when power drawn by the load drops below the above surge limits
Power boost up to 150%: higher percentage of rated power can be provided for limited
time periods as follows:
• 150% for 5 sec
• 140% for 30 sec
• 120% for 5 min
• 110% for 30 min
4.4 Direct DuAl Ac inPut Architecture
for higher reliability and redundancy, direct AC input from Grid and Generator can be fed
simultaneously to separate AC Input Circuits. Only one AC source is selected at one time. When
both Grid and Generator are available simultaneously, Grid is given priority. Transfer from Grid
to Generator or from Generator to Grid is always routed through the inverter. Please see details
under "Synchronized Transfer of Power".
4.5 trAnSfer relAy Section
Transfer relay Section is used to either feed AC power to the battery Charger Section and at
the same time, pass through the AC power from the external AC input power source to the
load (As long as the external AC input power from Grid/Generator is available and is within the
programmed limits of voltage and frequency) or to transfer the load to the Inverter Section (In
case of loss of the external AC input power source or if this source is not within the programmed
limits of voltage and frequency). Typical transfer time is 16 milliseconds from Grid/Generator to
Inverter and <1ms from Inverter to Grid/Generator. heavy duty 70A (2x35A in parallel), Transfer
relay is used for reliable transfer of up to 300% surge power and for Neutral to Ground bond
Switching (40A rated for EVO-2212 and EVO-2224).
4.5.1 Ac transfer and output neutral to chassis ground bond Switching
As required by NEC and uL Standard 458, automatic switching of bonding between the Ou-
put Neutral and Chassis Ground has been provided in EVO through "Output Neutral to Chassis
Ground bond Switching relay" [K4 in figs 4.1(a) and 4.1(b)]. Switching is bonding as follows:
general Description & Principles of Operations
SAMLEX AMErICA INC. | 63