Chapter 5—System Configuration and Operation
Power Xpert C445 Global Motor Management Relay
MN042003EN—January 2019
www.eaton.com
81
Two Speed Two Winding Operation Mode
Description
The two speed motor starter operation mode accepts off/
slow/fast commands to control two speed motor
applications. A run slow command will activate Output
1(slow). A run fast command will activate Output 2(fast). A
stop command de-activates both of the outputs.
When transitioning from fast
R
slow, the C445 will
de-activate Output 2(fast) and will delay activating Output
1(slow) until the Control Switching Time expires, allowing the
motor time to slow down before transitioning to the slow
speed. The Control Switching Time parameter can be found
in the Operation Mode category in the Power Xpert
in
Control
Software Tool.
The C445 will issue a control fault when:
●
The RunSlow or RunFast command is active and phase
voltage is present and no phase current is detected.
●
A Stop command is active and current is detected.
Note:
Even with the control fault disabled, after de-activating
the present speed, the C445 will NOT transition to the
new speed until current readings decrease to zero.
●
Outputs 1 and 2 will be de-activated anytime the C445
experiences a fault/inhibit condition.
●
Output 1 – slow starter coil (NO)
●
Output 2 – fast starter coil (NO)
●
Output 3 – open for user configuration and function can
be selected by the user.
The AtRef (At Reference) bit in the Motor Control Status
register is set based on the following two conditions. At
Reference signals that the motor is up to speed.
1.
If motor current first exceeds 115% of the active
overload FLA rating and then decreases back below
115% of the active overload FLA rating, it is determined
the motor has come up to speed and the AtRef bit will
be set.
2.
If motor current exceeds 30% of the active overload FLA
rating and remains until after the Motor State Transition
to Run Delay from Start time expires the motor is
determined to be up to speed and the AtRef bit will be
set. This time delay parameter can be found in the
General Protections category in the Power Xpert
in
Control Software Tool.
Figure 78. Timing Diagram for the Two Speed Operation
Mode
Recommended User Interface Options for the
Two Speed Two Winding Operation Mode
Figure 79. C445UM: Monitoring User Interface
The Monitoring User Interface can be used with any
operation mode. If selected as a local control source, the
User Interface Start and Stop buttons are enabled in Two
Speed Two Winding. The screen provides selection and
indication of Slow/Fast status. Use the soft keys to select
Slow or Fast before pressing the Start button. When running,
the highlighted selection indicates speed. Users may
optionally disable local start or reset functionality if desired.
C445UM may still be used in Two Speed if the User Interface
is not the local control source. Start, Stop and Auto buttons
will be disabled. If pressed, the screen will notify the user
that this functionality is not enabled. Control Status LEDs
indicating running, stopped and Auto status will still function.
SLOW
FAST
Speed Transition Delay
Timing Diagram
Check for motor current = 0
Control Fault Delay
