Figure 2-4. SMM Sequence of Operations
SMM Functionality Flow Chart
Start Here
Legend
Note: When monitor frequency and
monitor power source levels are reached,
the system will remain in this state, during
normal generator operation. If an
overload occurs during operation, loads
will shed according to set parameters.
* Each priority setting above Priority 1 will increase delay time in 15 second increments, starting with 15 seconds at Priority 2.
** If the frequency drops below acceptable levels for the pre-determined durations, all modules will shed.
† During lock out, the module will continuously monitor power source. If utility returns before the 30 minute lock out is satisfied, the module will allow five minutes to elapse from utility return time, and then close the contact.
Note 1: If the frequency is under 58 Hz when a module attempts to close the contactor after a shed, the module will wait another 5minutes plus Priority delay before attempting to enable.
Note 2: The "Checks power source" block monitors frequency and will change state, Generator or Utility, after it detects 1 minute of stable operation in the new state.
Utility
Utility
Utility
000105b
Generator
Generator
Checks power source
Checks power source
Contact closes
Contact closes
Contact Closed
Checks frequency
SMM Monitoring
Lockout switch ON and
contactor OPEN
Up to 5 minute delay
before contactor closes
Monitors frequency**
5 minute delay
5 minute delay*
Module powers up
Contactor Open
Utility Outage –
Contact opens
Contact opens –
Load is shed for 5
minutes (Priority 1) or
more*
Contact opens –
30 minute lock out*†
Module returns to
normal utility operation
Checks power source
If frequency meets
acceptable levels
If frequency meets
acceptable levels
for 15 seconds
If <52Hz for 1s or
If <58Hz for 3.5s
If <52Hz for 0.5s or
If <58Hz for 3s
Generator
Pressing the TEST button will
immediately override all settings and
shed load. Loads will be established
again after five minutes, plus the
pre-established priority setting time.
To Next Page
Loading...
