Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 78
7.3.2 PEU Electrical Connections & Component Installation
Requirements
The 1204F Pump Electronics Unit and DEF Tank is supplied direct from the
factory in the form of loose parts. The following parts require mounting to the
machine chassis by the OEM.
7.3.2.1 DCU Main Power Relay
The DCU main power relay is required to manage the operation of the
Tenneco XNOx DCU. To ensure robust system performance, the power
supply to the DCU is controlled by the engine ECM during certain phases of
engine operation, such as startup and shutdown. The OEM is responsible for
sourcing a relay to control the DCU power supply and its specification must
meet that shown in table 7.5.
Parameter
Value
Coil current draw <300mA
N/O contact Current Rating 40A (12V) 20A (24V)
Temperature Range -40°C - +85°C
Vibration <4.5Grms
Table 7.5 Relay specification for customer sourced relays
7.3.2.2 Tenneco XNOx DCU & Pump Unit
The Tenneco XNOx DCU and pump unit is supplied by Perkins as a single
unit with all customer required connections terminated at a single 31 pin
interface. The XNOx controller is used to control the operation of the dosing
system and the pump unit to supply pressurized DEF to the DEF injector. The
XNOx pump unit also provides a post engine shutdown purge operation to
ensure all DEF is returned to tank to prevent component damage due to
freeze thaw events (more detail in section 16.3).
All connections to the XNOx DCU and the DEF pump are provided pre-wired
as part of a factory supplied harness as shown in figure 7.6. Customer
interface is provided via a 31 pin connector mounted at the end of a 300mm
long flying lead.