Samlexpower Evolution EVO-2212 Owner's Manual - page 60
60 | SAMLEX AMERICA INC.
Soft Start: The inverter design incorporates “Soft Start” feature with the following advan-
tages and protections:
- 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 other-
wise 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 problem-
atic 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 Cur-
rent during startup.
- If the power drawn by the load exceeds the above surge ratings, the inverter pro-
tects 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 Gird/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).
SECTION 4 |
General Description & Principles of Operations