Electronically Controlled Bypass (ECB) Opera- tion
Figure 6.4 Drive Display with Bypass Start Time Delay Active
6.1.9 ECB Run Permissive
General Information
With run permissive active, the drive sends a run request and waits for a remote response before notifying the motor to start. The response indicates the system is safe to operate. Run permissive operates from the keypad hand/off/auto select in drive or bypass mode. Run permissive is enabled by programming in the drive parameters.
Prior to Enabling Run Permissive
•Complete the
•Verify that the drive is programmed for the run permissive function. See the drive support materials for programming the run permissive function.
Operation
•A start command can be initiated from local hand start, serial communications, or a remote auto start signal through digital drive input terminals.
•In response to the start command, an output request is sent from the programmable drive relay to the external equipment (to activate a valve or damper, for example).
•When a return run signal on the digital input is received, the motor is started in either drive or bypass, depending upon which mode is active.
130BX244.10 |
| programming and wiring to the drive control |
| Run Permissive Function Setup | |
| • | See the drive manual or support materials for |
|
| terminals. |
| • | Wire the output run request to the drive output |
|
| terminals selected, and program the terminals for |
|
| run request. |
| • | Wire the input run command to the drive input |
|
| terminals selected, and program the terminals for |
|
| run permissive. |
Disable Run Permissive
•Disable run permissive through the drive parameters and terminal programming.
6.1.10 ECB Overload
General Information
An overload device provides overcurrent protection for the motor when running in bypass. The thermally activated overload monitors motor current and trips to remove power to the motor if a sustained overcurrent condition exists. A Class 20 overload is standard with a variable setting for motor current. Test and reset buttons are also provided. In drive mode, the drive provides current sensing and trip protection. Fuses provide quick action for high over current conditions.
Prior to Enabling Overload
•Verify that the overload current dial setting matches the motor FLA rating on the motor nameplate.
•If the motor FLA is greater or less than the range of the current dial, reconfirm that the motor HP and voltage are within the option panel (and drive) rating. If greater than the FLA rating, replace the panel with one of a proper rating.
CAUTION
MOTOR DAMAGE!
Repeated attempts to reset overload can cause motor damage. Correct the overload condition and let the overload and motor return to normal operating temperature before resetting. See motor manufacturer’s recommendations for time between start attempts. Failure to correct the overload condition and let the motor return to normal operating temperature could cause motor damage.