Overvoltage Protection (ANSI 59)

Presentation

Overvoltage protection (ANSI 59) constantly monitors the voltage level of power supplies. If the voltage level of an installation goes out of its acceptable limits, the information provided by overvoltage protection can be used to initiate appropriate action to restore good operating conditions in the installation.

The information provided by overvoltage protection is used to generate alarms and circuit breaker tripping when required. In addition, the constant 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.

Prerequisites

Overvoltage protection is available when the ANSI 27/59 - Under/Over voltage Digital Module is purchased and installed on a MicroLogic X control unit.

Overvoltage protection requires an external 24 Vdc power supply.

Overvoltage protection is compatible with:

MicroLogic 2.0 X, 5.0 X, 6.0 X, and 7.0 X control units for IEC standard
MicroLogic 3.0 X, 5.0 X, and 6.0 X control units for UL standard
MicroLogic X control units with firmware version greater than or equal to 002.000.002. Earlier firmware versions need to be updated.

Data from the Digital Module is available remotely through IFE/EIFE or IFM communication interfaces, if the IFE/EIFE or IFM firmware version is compatible with the Digital Module. For more information, refer to firmware compatibility of the communication interfaces.

Operating Principle

ANSI 59-1

ANSI 59-2

Overvoltage protection monitors either three phase-to-phase voltages (V12, V23, V31), or three phase-to-neutral voltages (V1N, V2N, V3N).

Overvoltage protection is of two types:

ANSI 59-1: each phase is monitored independently. The protection picks up when one of three monitored voltages reaches the threshold Vmax1.
ANSI 59-2: the three phases are monitored together. The protection picks up when all three monitored voltages reach the threshold Vmax2.

Each type of overvoltage protection, ANSI 59-1 and ANSI 59-2 can be disabled.

Both types of overvoltage protection operate according to a configurable time delay:

ANSI 59-1: the time delay tVmax1 starts as soon as the protection threshold is reached.
ANSI 59-2: the time delay tVmax2 starts as soon as the protection threshold is reached.

Overvoltage protection operates with a definite time characteristic.

NOTE: The selection of voltages to be monitored (phase-to-phase or phase-to-neutral) applies to both undervoltage and overvoltage protections. It is not possible to select different settings for each type of protection. The selection is made for all four types of protection: ANSI 27-1, ANSI 27-2, ANSI 59-1, and ANSI 59-2.

Inhibiting Protection

To inhibit the overvoltage protection (ANSI 59-1 or ANSI 59-2), both the following conditions must be met:

Inhibition is enabled on a specific protection (ANSI 59-1 or ANSI 59-2) by setting the Inhibition parameter to ON.
Inhibition of optional protections is activated by an input of the IO module. The function Inhibit Optional Protection must be assigned to an input of the IO module.

For more information about inhibiting optional protections, refer to Enerlin'X IO - Input/Output Application Module for One Circuit Breaker - User Guide.

NOTE: The overvoltage protections (ANSI 59-1 or ANSI 59-2) can be inhibited separately, or together.

Setting for All Under/Overvoltage Protections

Select the type of voltages to monitor before making other settings:

VLL phase-to-phase voltage selection (factory setting)
VLN phase-to-neutral voltage selection (this setting should only be selected with 4-pole circuit breakers or 3-pole circuit breakers with ENVT wired and configured)

It can be set as follows:

With EcoStruxure Power Commission software (password-protected)
With EcoStruxure Power Device app (password-protected)

Setting ANSI 59-1 Protection

The settings for overvoltage protection on one phase (ANSI 59-1) are:

Vmax1 mode: enables (ON) or disables (OFF) the protection
Vmax1 action: sets the result of overvoltage protection action as trip or alarm
- Trip: the circuit breaker trips and three events are generated (start, operate, and trip)
- Alarm: two events are generated (start and operate)
Vmax1 inhib: enables (ON) the protection to be inhibited by IO module
Vmax1: threshold of overvoltage protection on one phase
tVmax1: time delay of overvoltage protection on one phase

They can be set as follows:

With EcoStruxure Power Commission software (password-protected)
With EcoStruxure Power Device app (password-protected)

The dual settings function does not apply to overvoltage protection on one phase. When the dual settings function is enabled, overvoltage protection settings are the same whether set A or set B settings are activated.

Setting ANSI 59-2 Protection

The settings for overvoltage protection on all phases (ANSI 59-2) are:

Vmax2 mode: enables (ON) or disables (OFF) the protection
Vmax2 action: sets the result of overvoltage protection action as trip or alarm
- Trip: the circuit breaker trips and three events are generated (start, operate, and trip)
- Alarm: two events are generated (start and operate)
Vmax2 inhib: enables (ON) the protection to be inhibited by IO module
Vmax2: threshold of overvoltage protection on all phases (ANSI 59-2)
tVmax2: time delay of overvoltage protection on all phases (ANSI 59-2)

They can be set as follows:

With EcoStruxure Power Commission software (password-protected)
With EcoStruxure Power Device app (password-protected)

The dual settings function does not apply to overvoltage protection on all phases. When the dual settings function is enabled, overvoltage protection settings are the same whether set A or set B settings are activated.

Protection Settings

The following are the settings for ANSI 59-1 and ANSI 59-2:

Type	Settings	Unit	Setting range	Step	Factory setting	Accuracy
ANSI 27 ANSI 59	Voltage selection	–	VLL phase-to-phase/ VLN phase-to-neutral	–	VLL phase-to-phase	–
ANSI 59-1	Vmax1 mode	–	ON/OFF	–	OFF	–
	Vmax1 action	–	Alarm/Trip	–	Alarm	–
	Vmax1 inhib	–	ON/OFF	–	OFF	–
	Vmax1	V	20–1200	1	20	± 2%
	tVmax1	s	0⁽¹⁾–300	0.01	10.00	± 2%, ± 20 ms
ANSI 59-2	Vmax2 mode	–	ON/OFF	–	OFF	–
	Vmax2 action	–	Alarm/Trip	–	Alarm	–
	Vmax2 inhib	–	ON/OFF	–	OFF	–
	Vmax2	V	20–1200	1	20	± 2%
	tVmax2	s	0⁽¹⁾–300	0.01	10.00	± 2%, ± 20 ms
(1) When the time delay is set below 50 ms, overvoltage protection can trip on transient phenomena, such as overvoltages caused by atmospheric disturbance.

Protection Characteristics

Characteristics of overvoltage protection:

Definite time delay
Instantaneous reset time
Hysteresis: fixed 98%
Minimum breaking time 50 ms
Maximum breaking time 140 ms with time delay set to 0 s

Predefined Events

The function generates the following predefined events:

Code	Event	History	Severity
0x6411 (25617)	Overvoltage on 1 phase trip	Trip	High
0x6211 (25105)	Overvoltage on 1 phase start	Protection	Low
0x6311 (25361)	Overvoltage on 1 phase operate	Protection	Medium
0x642B (25643)	Overvoltage on all 3 phases trip	Trip	High
0x622B (25131)	Overvoltage on all 3 phases start	Protection	Low
0x632B (25387)	Overvoltage on all 3 phases operate	Protection	Medium
0x0EF8 (3832	Optional protection inhibited by IO module	Protection	Low
0x0D0C (3340)	Config error IO/CU: optional protection Inhibit	Configuration	Medium

Predefined events cannot be modified by the user. For general information about events, refer to Event management.

Protection events are generated as follows:

The start event is generated when the protection picks up.
The operate event is generated when the protection time delay elapses.

The operate event is not generated when the optional protection is inhibited.
The trip event is generated when the circuit breaker tripping voltage release (MITOP) activates.

The trip event is not generated when:
- The optional protection is set in alarm mode
- The optional protection is inhibited

Recommended Actions

Code	Event	Recommended actions
0x6411 (25617)	Overvoltage on 1 phase trip	Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app.
0x642B (25643)	Overvoltage on all 3 phases trip	Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app.
0x0D0C (3340)	Config error IO/CU: optional protection Inhibit	Correct the configuration error with EcoStruxure Power Commission software: If you want optional protection inhibition to be controlled by IO module, connect an IO module with inhibit optional protection assignment. If you do not want optional protection inhibition to be controlled by IO module, connect an IO module without inhibit optional protection assignment.

Code

Event

Recommended actions

0x6411 (25617)

Overvoltage on 1 phase trip

Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app.

0x642B (25643)

Overvoltage on all 3 phases trip

Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app.

0x0D0C (3340)

Config error IO/CU: optional protection Inhibit

Correct the configuration error with EcoStruxure Power Commission software:

If you want optional protection inhibition to be controlled by IO module, connect an IO module with inhibit optional protection assignment.
If you do not want optional protection inhibition to be controlled by IO module, connect an IO module without inhibit optional protection assignment.

Resetting a Trip Event

For information about resetting the circuit breaker after a trip due to an electrical fault, refer to the relevant document:

MasterPacT MTZ1 - Circuit Breakers and Switch-Disconnectors - User Guide
MasterPacT MTZ2/MTZ3 - Circuit Breakers and Switch-Disconnectors - User Guide