Technical Note: TN0025 - Rev 09

SP PRO Generator Controller Wiring Guide


The SP PRO can be connected by default to both two and three wire generator controllers. Seven different schemes are detailed in this document:
  • Two Wire Run
  • Two Wire Start / Stop
  • Three Wire On / Start – Type 1
  • Three Wire Start / Stop
  • Three Wire Preheat / Run
  • Three Wire Run / Stop
  • Three Wire On / Start – Type 2

Wiring

The following diagrams illustrate the expansion card connections needed for each control scheme. Note that the relay outputs are voltage free change-over switches – max 60 V, 500 mA.

Two Wire Run

This configuration is used when the generator controller requires two wires to be closed to start and Run and then opened to stop the generator.


The Start Relay is not used and Start Delay and Start Time settings have no effect in this configuration.

Two Wire Start / Stop

This configuration is used when the generator controller requires two wires to be momentarily closed then opened to Start and run and the same again to Stop the generator.


Check the generator controller documentation to ensure that the Start Time, which is the time the wires remain closed for, is sufficient to be acted upon. Testing if the generator starts and stops correctly will determine if the default two seconds is suitable.

The Run Relay is not used and the Start Delay time setting has no effect in this configuration.

Three Wire On / Start – Type 1

This configuration is used when the generator controller requires:

  • One wire to be closed to a common wire to turn the controller On.
  • Another wire to be momentarily closed then opened to the common wire to Start the generator.
  • The generator is stopped when the On wire is opened.

Check the generator controller documentation to ensure that the Start Delay, which is the time between the controller being turned on and when the start relay closes, and the Start Time, which is the time the wires remain closed for, is sufficient to be acted upon. Testing if the generator starts and stops correctly will determine if the default two seconds is suitable.

Three Wire Start / Stop

This configuration is used when the generator controller requires:

  • One wire to be momentarily closed then opened to a common wire to Start the generator.
  • Another wire to be momentarily closed then opened to the common wire to Stop the generator.

Check the generator controller documentation to ensure that the Start Time, which is the time the wires remain closed for, is sufficient to be acted upon. Testing if the generator starts and stops correctly will determine if the default two seconds is suitable.

The Start Delay setting has no effect in this configuration.

Three Wire Preheat / Run

This configuration is used when the generator controller requires:
  • One wire to be momentarily closed then opened to a common wire to Preheat generator. 
  • Another wire closed to a common wire to Start and Run, and then opened to Stop the generator.

Check the generator documentation to ensure that the Start Time, which is the time the Preheat wire will remain closed for, is sufficient to allow engine starting in all conditions. The default of 2 seconds is unlikely to be suitable.

The Start Delay setting must be set to minimum (0.5s) in this configuration.

Three Wire Run / Stop

This configuration is used when the generator controller requires:

  • One wire closed to a common wire Start and Run the generator. 
  • Another wire and momentarily closed then opened to a common wire to Stop the generator.

Check the generator controller documentation to ensure that the Start Time, which is the time the Stop wire will remain closed for, is sufficient to be acted upon. Testing if the generator stops correctly will determine if the default two seconds is suitable.

The Start Delay setting has no effect in this configuration.

Three Wire On / Start – Type 2

This configuration is used when the generator controller requires:

  • One wire to be closed to a common wire to turn the controller On.
  • Another wire to be momentarily closed then opened to the common wire to Start the generator.
  • The generator is Stopped when the On wire is opened and the Start disconnected from common.


Settings

All of the wiring examples use the default SP LINK generator controller configuration. These settings are applied by default after selecting an auto-start generator using the Site Configuration Wizard.


Generator Controller



Generator Control Outputs


Tip: 'Start' output is for pulse signals. Only a 'run' output needs to be configured for most two-wire start generators.

Generator Input Power Limit

~85% of generator nameplate rating recommended for stable operation. 


Normal SoC Start and Stop

Image Placeholder

Signal Timing Graph

The below graph depicts the relative timing for the Generator Run and the Generator Start signals.

When the generator is requested to start (A), the Generator Run signal is immediately asserted. After a delay equal to the Start Output Delay (A to B) the Generator Start signal is asserted (B) for a duration equal to the 
Start Output Time (B to C).

When the generator is requested to stop (D) the Generator Run signal is immediately de-asserted at the same time that the Generator Start signal is asserted for a duration for a duration equal to the Start Output Time (D to E).




Commissioning

Refer to the Commissioning section checklist in the SP PRO Instruction Manual.


Troubleshooting

When the SP PRO's generator LED is flashing red it typically indicates an inability to synchronise with the generator output.


Firstly, make sure the generator is not out of fuel and has been switched to auto-start.

In most cases, the problem can be identified by observing the readings under Data View > Now. The 'AC source status' indicates whether or not the source voltage and frequency is within tolerance. After the being in tolerance for a short time the SP PRO will synchronise with the AC waveform (output mode becomes 'sync') and the AC source transfer contactor should close.




If the AC source is not within tolerance, the user can make adjustments under the AC Source settings.




The SP PRO will reactivate the auto-start relay if it does not detect a suitable AC source within a period of time. If the generator takes rather long to start up the user can increase the 'Confirm Start Time.'


Additional Information
Visit the Selectronic: Knowledge Base or contact Selectronic via the Customer Portal.