2.2.2
Feature Additions
Improvements in PECM3-CTL from PECM-CTL
● Seven I
2
C connectors are provided compared to 4 on the previous PECM-CTL, eliminating
the need for a Wiring Distribution Board (WDB).
● An Atmospheric pressure sensor has been added.
Improvements In PECM2 Assembly from Original PECM
The PECM design has changed since its original release. The newest version of this part is
also used as the spare-part replacement for the previous version. The original PECM was a
single electronic circuit board with a metal protective shield. It provided connection points for
the electrical power coming into the Maxum GC and mounted low power electrical relays which
could switch power to any electrical heater with a power rating of less than 200 watts.
The newest version of the module, PECM2, is a two part circuit board. One part connects the
electrical power. The other part includes certain electronic circuits. Key features of the newer
design are:
● Easy access (no cover)
● Two on-board temperature control circuits. May allow elimination of a DPM that is only used
for temperature control, such as for heated valves or the methanator.
● Additional medium-wattage heater circuit
● Four connectors providing I
2
C and 24VDC power distribution have been added. This
replaces some of the functions of the Wiring Distribution Board (WDB).
● Includes solenoid valve control which eliminates the need for individual SVCM controller
boards. When converting an older analyzer and eliminating original SVCM controller
boards, additional long cables are required.
● Improved low-profile fuse holders
● LED indicators for air pressure switch on air-bath heater circuits
● Built-in provision for connection of Uninterruptible Power Supply (UPS) for 24VDC circuits.
The heaters are powered through different connectors to minimize the loading of the AC
power needed for running the 24VDC circuits.
Electronic Compartment Component Descriptions and Maintenance Procedures
2.2 Power Entry and Control Module
Maxum II Reference Manual
Manual, 7/2017, 2000596-001
19
