DECS-100 Maintenance and Troubleshooting
7-6
If there is an open circuit, repair as necessary.
If there is no open circuit, proceed to Step 5.
Step 5.
Verify that all connections are correct according to Figures 4-6 through 4-9.
If connections are incorrect, correct the problem.
If connections are correct, proceed to Step 6.
Step 6.
Verify that the load being applied to the generator for droop testing is not purely resistive.
If only a resistive load is being applied to the generator, apply an inductive load and retest.
If the load being applied to the generator is inductive, proceed to Step 7.
Step 7.
Verify that your DECS-100 is compatible with the current sensing transformer (1 A or 5 A
secondary) being used. For example, a current sensing transformer with a 1 ampere output rating
would produce very little droop if your DECS-100 has a 5 ampere current transformer input. Refer
to Figure 1-1 of Section 1, General Information to check the current transformer input of your
DECS-100.
If the current transformer input is incorrect, replace the current sensing transformer or the
DECS-100 for compatibility.
If the current transformer input is correct, proceed to Step 8.
Step 8.
If the above steps fail to correct the malfunction, replace the DECS-100 unit.
No Voltage Matching
Step 1.
Verify that the Voltage Matching option was purchased and is enabled in the software.
If not enabled, use the BESTCOMS software to turn on voltage matching.
If voltage matching is enabled, proceed to Step 2.
Step 2.
Verify that all connections are correct according to Figures 4-6 through 4-9 as required for the
Voltage Matching option of the DECS-100.
If the interconnection is incorrect, reconnect according to the appropriate interconnect diagram.
If the interconnection is correct, proceed to Step 3.
Step 3.
Verify that the DECS-100 VM/VMC contact input is closed.
If the VM/VMC contact input is open, it must be closed to enable voltage matching.
If the VM/VMC contact input is closed, proceed to Step 2.
Step 4.
Check for correct utility reference voltage on DECS-100 terminals B1 and B3.
If the interconnection is incorrect, reconnect according to the appropriate interconnect diagram.
If the interconnection is correct, check for open system fuses.
Verify that the potential sensing transformer, if used, is connected to DECS-100 terminals B1 and
B3.
If potential sensing transformer connections are correct, proceed to Step 5.
Step 5.
Verify that the generator output voltage setpoint is within 10 percent of the measured utility bus
voltage.
If the setpoint is too low or too high, adjust the setpoint to the appropriate level.
If the setpoint is correct, proceed to Step 6.
Step 6.
If the above steps fail to correct the Voltage Matching malfunction, replace the DECS-100.