Panel to ESM(r) Interfacing
Overview
The Waukesha ESM (r) is an engine control unit made by Waukesha for their VHP series engines. When a unit with an ESM is connected to an EMIT panel, the panel will use a few signals to control the start, stop, and speed of the engine. Many concepts are similar to connecting to other engines.
Initial Setup
Navigate to Settings - Brain - Outputs Setup - ECU Selection, and select "Waukesha ESM".
Panel to ESM Connections
There are three discrete connections from the panel to the ESM: Run permissive, start initiate, and emergency stop. There is also one analog connection for target speed. The schematic should show a page where these land in that specific panel. The details of each signal is noted below.
ESM Normal Run
The ESM normal run wire is numbered 1611 from the engine. This wire needs 24VDC maintained to run. In the EMIT panel this will be powered from a relay that will be ON during run. Usually this relay coil is powered from the fuel valve output of the brain (Pin 10) or a digital output that is set to Fuel valve or Driven equipment ready. This relay will come on during the start sequence and turn off when the unit should shut down.
ESM Normal Start
The ESM normal start wire is numbered 1609 from the engine. This wire is pulsed with 24VDC for a second or two to start the engine. On the EMIT panel it will always be controlled from relay CR2 from output DO-2. This relay / output will turn on for a couple seconds during the start sequence when the start initiate should begein.
ESM Emergency Shutdown
The ESM emergency stop wire is numbered 1606. This wire needs 24VDC maintained to run. In the EMIT panel this will be routed through the cabinet E-stop switch and back to power, so that if the switch is pushed in the power is removed from the ESD wire.
ESM Speed Target Signal
The ESM speed target is a pair of wires that are numbered 1614 for signal and 1613 for return. These are an analog input on the ESM for the speed target. On the EMIT panel analog out 1 of the brain is always used for the speed target, which wires to this pair. AO-1 will go to the signal wire and the ground return will go to normal panel ground. In speed control setup the 4-20 mA range will match the idle to rated speed of the engine.
