A customer may want to replace the CM4000 unit without disconnecting the CT's and PT's from the Current/Voltage Transient Module (ie. decouple the CVM module from existing CM4000 and install into new CM4000)
CM4000 Series Meters
Shorting CT's and disconnecting line voltages to the CVMT may be difficult and/or time-consuming when trying to replace the CM4000 series meter.
*Warning: Installation and maintenance of this device should only be performed by qualified, competent personnel that have appropriate training and experience with high voltage and current devices. Failure to follow the instructions / warnings in the Meter Installation Guide can result in permanent damage to the meter, severe injury or death.
The meter must not be replaced while the CVMT is still connected to line voltage and transformer current.
It is EXTREMELY DANGEROUS to remove the existing CVMT module from CM4000 without first disconnecting incoming line voltages and shorting and then disconnecting the CTs
It is possible to install/remove CVM/CVMT module in the field, but all power sources (including PT, CT, I/O, COM, and auxiliary power) supplying to this equipment must be turned off before working on or inside equipment.
Failure to observe these instructions will result in death or serious injury.
This is made clear in both the Reference Guide and Installation Guide publications for the CM4000 Series devices via warnings such as the following:
NOTE: CT shorting blocks are ALWAYS required to be installed between CT and meter for the repair/replacement. This is clearly stated, repeated, emphasized, and depicted in all wiring diagrams contained in the Installation Manual.