Relay Controlled Fuse Groups
Overview
A Relay Controlled Fuse Group is a specific type of functional group that includes a fuse, a switch, and a relay. There are two different fuses required: one outside and upstream from the group (referred to here at the main fuse) and the fuse inside the group, referred to as the controlled fuse.
The image below displays a typical example.
Figure 1: Relay Controlled Fuse Group Example
Relay Controlled Fuse Group Conditions
The following conditions must be met for the group to be valid:
- There must be a main fuse upstream from the controlled fuse, with no more than two buses between the main and controlled fuses.
- The main fuse must be set to a device library style that has the Relay Controlled Fuse Group check box selected. In addition, the model must be set to the first model for that style.
- The fuse group must contain a fuse (the controlled fuse), a switch, and a relay.
- The fuse that is inside the group (the controlled fuse) must be set to a device library style that has the Relay Controlled Fuse Group check box selected in the library. In addition, the model cannot be set to the first model for that style.
- The controlled fuse and the switch must be in parallel to each other.
- The relay must be downstream from the fuse and switch.
- The relay must have at least one phase or maintenance phase type function that points to a valid CT. This is set up in the Relay Data dialog box, on the Specifications tab, under the Dev Fctn Type and CT columns.
- There must be at least one bus downstream of the CT.
- All of the items must be connected and active.
You will receive a warning if you open the Coordination focus and the required conditions for the functional group are not met.
More Information
| Functional Groups | |
| Relay Controlled Fuse Group Data | |
| Relay Controlled Fuse Group Settings |
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