THOMSON MEC 2 - V1.4 - Control Output Contact Descriptions

MEC 2 MICROPROCESSOR ENGINE/GENERATOR CONTROLLER
PM056 Rev 6 05/10/15 Thomson Technology
26
Note: Low Oil Pressure shutdown may alternately be programmed and
wired as a digital fault input contact. Refer to Section 9.5
for further
details.
4.4.6. ENGINE SPEED ANALOG INPUT
The MEC 2 engine speed sensor measures AC voltage and frequency from an
engine mounted magnetic pick-up. The engine speed sensor provides
information to perform the following control functions:
Over speed shutdown
Crank Disconnect control
Loss of speed signal detection
Starter Re-engage control
RPM display
Refer to the programming instructions for further information.
5. CONTROL OUTPUT CONTACT DESCRIPTIONS
All output contacts from the MEC 2 Engine Controller are non-powered (i.e. dry contacts) and
are rated 10A/240VAC, 8A/28Vdc resistive (3A inductive, 0.4pf). Output contacts are not fused
therefore external over current protection (maximum 10A) is required for all control circuits using
these contacts. Contacts indicated on schematic drawings and connection diagrams are shown
in a de-energized state and will change state upon activation of the specific control function.
5.1. RUN, CRANK OUTPUT CONTACTS
The MEC 2 Controller provides two dedicated output contacts for basic control and
alarm circuits as described below:
5.1.1. RUN OUTPUT
The Run output contact is a Form A dry contact and is used to control the
engines “run” circuit. This typically includes external control devices such as
“fuel rack solenoids” or electronic governors. Note: An additional pilot relay will
be required to energize high current devices that exceed the 10A resistive rating.
The run output control logic provides an “energize to run signal” (i.e. the run
contact closes when a run condition is activated). Note: For energize to stop
control logic, refer to the programmable output control function.