SAMLEX AMERICA INC. | 53
APPENDIX A
4.5.2.7.1 Programming Steps for Parameter "LOW RESET"
Enter Key Up Key Enter Key Up Key x 6 times Enter Key
A N Y O P E R A T I N G
M O D E S C R E E N
ð
S E L E C T G R O U P
C H A R G E C U R V E
ð
S E L E C T G R O U P
I N P U T S E T T I N G
ð
D E F A U L T F R E Q
0 = 6 0 H z
ð
L OW R E S E T
5 6 . 0 0 H z
ð
K E Y I N P A S S WO R D
0 0 0 0
Password 8052
See Section 4.3.1
ð
L OW R E S E T
5 6 . 0 0 H z
4.5.2.8 SYNC GRID
(Table 4.4, Parameter Setup Screen No.8)
In EVO™, the frequency and phase of the Inverter Section are always kept synchronized with the AC input source
connected to terminals marked “GRID”
(4,5,6 in Fig 2.3)
. This facilitates faster and safer transfer of power between the
Inverter Section and the AC input source.
For supplementary details on synchronized transfer of AC power, please refer
to Sections 4.5.4 to 4.5.7 of the Owner’s Manual for EVO-2212/3012/2224/4024
.
Parameter “SYNC GRID” is used to program the desired
sensitivity
of frequency and phase synchronization of the Inverter
Section with the AC input voltage fed at the AC Input Terminals marked “GRID”
(4,5,6 in Fig 2.3)
. 2 programming
options are available for this parameter: (i)
Option “0= Fine”
(Default option) – see Section 4.5.2.8(a) below and (ii)
Option “1= Coarse”
– see Section 4.5.2.8(b) below.
When EVO™ is operating in Inverting Mode
(there is no AC input)
, its output frequency will be equal to the frequency
that has been selected by the programming parameter “DEFAULT FREQ” i.e. 60Hz (Default) or 50Hz
(See TABLE 4.4
and Section 4.5.2.1)
. When AC input is made available at AC Input Terminals marked “GRID”
(4,5,6 in Fig 2.3)
, it is first
monitored for 2 sec. If it is within the programmed values of (i) frequency limits
(TABLE 4.4)
, (ii) low voltage limits
(TABLE
4.5)
and (iii) high voltage limits
(TABLE 4.6)
, synchronization process is initiated to synchronize the frequency and phase
of the Inverter Section with the incoming AC input voltage. Details are given below:
a) Parameter SYNC GRID set at Option “0= Fine” (Default)
This is the “
Default Setting
”. This setting is applicable when Grid / Inverter Generator is connected to AC
Input Terminals marked “GRID”
(4,5,6 in Fig 2.3)
. Synchronization control logic used in this option is suitable
for more stable frequency output of Grid / Inverter Generator. Under this option, the frequency and phase of
the Inverter Section are synchronized with the Grid as follows:
i. First, the frequency of the Inverter Section is tracked in steps of 0.1Hz per cycle and made equal to
the frequency of the Grid / Inverter Generator input.
ii. Then, the phase of the Inverter voltage relative to the Grid voltage is tracked by 1º per cycle. When
the phase of the Inverter voltage is within ± 3.5º of the input voltage waveform, the Transfer Relay
is activated to transfer the AC load from the Grid / Inverter Generator to the Inverter Section at zero
crossing of the voltage waveform.
b) Parameter SYNC GRID set at Option 1= Coarse
This setting is selected if a Generator is connected to AC Input Terminals marked “GRID”
(4,5,6 in Fig 2.3)
.
As compared to very stable frequency of Grid /
Inverter Generator
, the frequency of a Generator may vary
considerably depending upon the performance of its Speed Governor that compensates for the drop in RPM
/ frequency when electrical load is switched on / increased or, rise in RPM / frequency when electrical load is
decreased /switched off. Hence, if synchronization sensitivity set is at “0= Fine” as in Section 4.5.2.8(a) above,
it may take very long for the Inverter Section to synchronize with the Generator or, may not synchronize at
all. Under this option, the frequency and phase of the Inverter Section are synchronized with the Generator
differently
as follows:
SECTION 4 |
Parameter Setup