Specifications
Power Entry and Control Module–Direct Current (PECM-DC), Continued 
The Maxum II Modular Oven is typically installed with an internal 24V 
power supply that supports a wide range of AC power input options. 
DC Power Input 
(Optional) 
In addition to AC input, the PECM-DC allows for power via external 24V 
DC supply. In this configuration the internal DC power supply is not 
installed. The requirements for this configuration are detailed in the 
specification table at the beginning of Chapter 1 of this manual. 
The connections to the PECM-DC are shown in figure 2-16 below. 
Connections 
Figure 2-16: PECM-DC Connections 
One function of the PECM-DC is to monitor the state of the purge 
condition for the analyzer, if purge is required. The atmospheric 
reference is connected to the outside via a tube. If the switch detects that 
the pressure difference between internal and external drops below the 
required threshold (pressure difference of at least 05 inches water), then 
the switch is enabled. This sends a signal via the purge signal cable to 
the CIM, which illuminates the purge fault LED and creates a purge 
alarm. 
Purge 
When a purged enclosure is not required per the safety codes, connector 
IP1 on the PECM-DC can be used to disable the purge alarm. Refer to 
Figure 2-16 for connector locations. 
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