Issue: ANSI 27/59 Under/Over Voltage Protection and its Applications, 1. will it trip the breaker on complete power loss? 2. How is it configured?
Product Line: Circuit Breakers
Environment: Masterpact MTZ Micrologic X Control Units
Resolution:
1a. If you have a UPS or battery back up on the Control Unit 24Vdc power supply the undervoltage protection will trip the breaker on complete power loss.
1b. If the Control Unit 24Vdc power supply drops out with the complete power loss, then it will not trip the breaker on most of the delay time thresholds. It takes about 50mS for the control unit (CU) to power down by itself. It takes less than 1000mS to power down using a power supply on the CU. The capacitance in the power supply will be the variable in this equation for how long it takes the CU to power down. Use delay times greater than 1 second if you desire a "no trip" function on complete power loss.
2. The under voltage/over voltage protection cannot be configured from the control unit HMI, but rather from the MTZ app or Ecostruxure Power Commission (EPC, formerly known as Ecoreach).
Additional Information from the Masterpact MTZ catalog 0614CT1701:
The Under/Over Voltage Protection digital module monitors the circuit breaker voltages
and trips when the voltage exceeds the settings.
The voltage in electrical installations must be maintained between a minimum value
and a maximum value, generally the rated operating voltage ±10%. Beyond these
limits the operation and performance of the loads may be impacted. Under/overvoltage
protection monitors the system voltage so that if the voltage level of an installation
goes out of its acceptable limits, appropriate action can be taken.
Description
This module monitors the voltages V12, V23, V31 or V1N, V2N, V3N, and trips the
circuit breaker if the voltage exceeds the settings. For ANSI 27-1 and 59-1 the
protection activates when one of the three monitored voltages reaches the designated
upper or lower limit. For ANSI 27-2 and 59-2 the protection activates when all the three
monitored voltages reaches the designated upper or lower limits.
NOTE: The Under/Over voltage protection requires the Micrologic X control unit to
be supplied by an external 24 Vdc power supply.
For each undervoltage protection, ANSI code 7, and overvoltage protection, ANSI
code 59, the user can choose to monitor either the three phase-to-phase voltages V12,
V23, V31, or the three phase-to-neutral voltages V1N, V2N, V3N.
The selection applies for both undervoltage and overvoltage protections. It is not
possible to select phase-to-phase voltages for undervoltage monitoring and phase-toneutral
voltages for overvoltage monitoring and vice versa. Under and overvoltage
protections operate according to a definite time characteristic. One adjustable timedelay
is associated to each of the four elements. The time-delay starts as soon as the
protection picks up. Each element generates the start, operate and trip events (see
Micrologic X Optional Protection Modules, page 50) . When the undervoltage
protection is set in tripping mode, the voltage measurement must be performed on the
power source side to allow the circuit breaker closing. Standard installation has the
Micrologic X control unit voltage input directly connected to the internal pickup voltage
on the bottom side of the circuit breaker.
Consequently:
• If the circuit breaker is bottom-fed, the internal pickup voltage is suitable for
undervoltage protection and circuit breaker closing.
• If the circuit breaker is top-fed, an external voltage input is required. The PTE
option must be selected to perform the voltage measurement on the power source
side.
The protection trips when:
• the value of voltage exceeds the setting.
• the associated timer is elapsed.
Benefits
The information is used to generate alarms and, when required, open the circuit
breaker.
The Undervoltage/Overvoltage Protection digital module is suitable for generator
protection.
The permanent monitoring of phase-to-phase or phase-to-neutral voltages enables
appropriate action to be initiated to safeguard the operation of the installation during
abnormal or critical situations, for example: load shedding, source change-over, and
emergency generator starting.
Product Line: Circuit Breakers
Environment: Masterpact MTZ Micrologic X Control Units
Resolution:
1a. If you have a UPS or battery back up on the Control Unit 24Vdc power supply the undervoltage protection will trip the breaker on complete power loss.
1b. If the Control Unit 24Vdc power supply drops out with the complete power loss, then it will not trip the breaker on most of the delay time thresholds. It takes about 50mS for the control unit (CU) to power down by itself. It takes less than 1000mS to power down using a power supply on the CU. The capacitance in the power supply will be the variable in this equation for how long it takes the CU to power down. Use delay times greater than 1 second if you desire a "no trip" function on complete power loss.
2. The under voltage/over voltage protection cannot be configured from the control unit HMI, but rather from the MTZ app or Ecostruxure Power Commission (EPC, formerly known as Ecoreach).
Additional Information from the Masterpact MTZ catalog 0614CT1701:
The Under/Over Voltage Protection digital module monitors the circuit breaker voltages
and trips when the voltage exceeds the settings.
The voltage in electrical installations must be maintained between a minimum value
and a maximum value, generally the rated operating voltage ±10%. Beyond these
limits the operation and performance of the loads may be impacted. Under/overvoltage
protection monitors the system voltage so that if the voltage level of an installation
goes out of its acceptable limits, appropriate action can be taken.
Description
This module monitors the voltages V12, V23, V31 or V1N, V2N, V3N, and trips the
circuit breaker if the voltage exceeds the settings. For ANSI 27-1 and 59-1 the
protection activates when one of the three monitored voltages reaches the designated
upper or lower limit. For ANSI 27-2 and 59-2 the protection activates when all the three
monitored voltages reaches the designated upper or lower limits.
NOTE: The Under/Over voltage protection requires the Micrologic X control unit to
be supplied by an external 24 Vdc power supply.
For each undervoltage protection, ANSI code 7, and overvoltage protection, ANSI
code 59, the user can choose to monitor either the three phase-to-phase voltages V12,
V23, V31, or the three phase-to-neutral voltages V1N, V2N, V3N.
The selection applies for both undervoltage and overvoltage protections. It is not
possible to select phase-to-phase voltages for undervoltage monitoring and phase-toneutral
voltages for overvoltage monitoring and vice versa. Under and overvoltage
protections operate according to a definite time characteristic. One adjustable timedelay
is associated to each of the four elements. The time-delay starts as soon as the
protection picks up. Each element generates the start, operate and trip events (see
Micrologic X Optional Protection Modules, page 50) . When the undervoltage
protection is set in tripping mode, the voltage measurement must be performed on the
power source side to allow the circuit breaker closing. Standard installation has the
Micrologic X control unit voltage input directly connected to the internal pickup voltage
on the bottom side of the circuit breaker.
Consequently:
• If the circuit breaker is bottom-fed, the internal pickup voltage is suitable for
undervoltage protection and circuit breaker closing.
• If the circuit breaker is top-fed, an external voltage input is required. The PTE
option must be selected to perform the voltage measurement on the power source
side.
The protection trips when:
• the value of voltage exceeds the setting.
• the associated timer is elapsed.
Benefits
The information is used to generate alarms and, when required, open the circuit
breaker.
The Undervoltage/Overvoltage Protection digital module is suitable for generator
protection.
The permanent monitoring of phase-to-phase or phase-to-neutral voltages enables
appropriate action to be initiated to safeguard the operation of the installation during
abnormal or critical situations, for example: load shedding, source change-over, and
emergency generator starting.
Released for:Schneider Electric USA
