GEMotor Protection System Integrated process, control, and protection for low voltage motors

or generate an alarm when the voltage 

drops below a specified voltage setting for 

a programmable time delay.

Overvoltage

An overvoltage on running motor with a 

constant load results in decreased current. 

However, iron and copper losses increase, 

causing an increase in motor temperature. 

The current overload relay will not pickup 

this condition and provide adequate 

protection. The overvoltage element may 

be used for protecting the motor in the 

event of a sustaine overvoltage condition.

Contactor Failure

The MM2 monitors the contactor while 

performing start and stop commands. If 

the contactor does not change status an 

‘open control circuit’ or ‘welded contactor’ 

alarm is triggered.

Additional Alarms

The MM2 has programmable alarms to 

warn of a number of abnormal conditions. 

These in­clude: acceleration time exceeded, 

abnormal inverter starter, in­complete start, 

motor greasing, contactor inspection, 

motor stop time, analog input, and process 

interlock switch open.

Starters 

MM2 can be programmed to serve as the 

following types of motor starters:

• Full Voltage non-reversing,

• Full Voltage reversing,

• Wye/Delta open or close transition 

starter,

• Two speed starter,

• Inverter (VSD) starter,

• Slip ring (rotor resistors) and primary 

resistance starters,

• Autotransformer open or close 

transition starter,

• Duty/Standby starter,

• Soft starter

Undervoltage Auto Restart

The motor can be automatically restarted 

after a momentary power loss when this 

feature is enabled. When the control 

voltage drops below the dropout voltage 

the contactors are de-energized. The MM2 

can initiate timers to restart selected drives 

upon the return of supply voltage. If control 

voltage is restored within the programmed 

restart time, the motor will be restarted 

immediately. If the control voltage takes 

longer to be restored, the MM2 can be 

programmed to attempt a restart after a 

programmed time delay.

Outputs 

The MM2 has one or two contactors (A 

and B) which are used for motor starting. 

There are also two auxiliary programmable 

output relays available on the MM2, 

which can be assigned to any one of 31 

functions.

Switched Inputs 

The MM2 has up to six fixed control inputs. 

These are used for start A and B, stop, local 

isolator, and contactor A and B status. The 

MM2 also has up to 10 programmable 

switch inputs. Each input can have one 

of 33 interlock functions assigned to it. A 

function can be assigned to one interlock 

input only.

Analog Input

The analog input can be scaled to user 

defined values. High and low alarm and trip 

setpoints are recorded with time delays. 

Monitoring and Metering

The MM2 offers advanced monitoring and 

metering which includes:

Metering

The MM2 meters and displays:

• current of each phase

• Ground fault leakage current

• Motor load as a % of full load current

• Thermal capacity used (%)

• % Current unbalance

• Power (kW)

• Energy (kWh)

• Voltage

• Analog input

Trip Record

When the MM2 issues a trip command a 

record is generated which includes the 

cause and pre-trip actual values.

Statistics and Maintenance

The MM2 records statistical data about 

relay and motor operation, allowing the 

user to set the interval at which routine 

maintenance tasks should be performed. 

When the times are exceeded an alarm is 

generated. These include:

• Motor greasing interval: number of 

hours between bearing lubrication

• Contactor inspection: number of starts 

after which the contactor contacts 

must be inspected for wear

• Maximum motor stopped time: the 

maximum number of hours the motor 

can be left shut down

User Interfaces

When ordered with the Panel Mount 

option, the MM2 comes equipped with a 40 

character display, LED indicators, as well 

programming and control push buttons.

Display and Keypad

The MM2 has a keypad and 40 character

display for local control and programming

without a computer. In the event of a

trip, alarm, or start block, the display will

automatically display a clear status 

message.

In addition to the programming keys, the 

panel mount option also provides 3 control 

keys for starting and stopping the motor 

locally. 

Indicator LEDs

The panel mount MM2 has nine LED’s that 

provide the status of the motor and relay 

output contacts. Two additional LED’s 

indicate whether the relay is in Auto or 

Manual control mode.

Communications

The MM2 uses a ModBus® RTU RS485 

connection for communication. Up to 32 

MM2s can be daisy-chained together on a 

single communication channel. The MM2 

supports a number of baud rates, ranging 

from at 1200 to 19,200 bps. A RS232/485 

converter module may be used to connect 

a personal computer to the MM2.

Software

The MM2 comes with a Windows®-based 

configuration program called MM2PC. It 

allows access to all the features of the 

MM2 with easy to use, pull-down menus.