The MiCOM P220 and P225 make up Schneider Electric's P22x range, motor and overcurrent protection relays widely installed in industry. The P241, P242 and P243 are the Easergy MiCOM P24x range for medium and large rotating machines, induction and synchronous; the P243 adds motor differential. They are configured with Easergy Studio.
What it is and where it is used
The MiCOM P220 and MiCOM P225 make up Schneider Electric’s P22x range, motor and overcurrent protection relays. The MiCOM P241, P242 and P243 make up the Easergy MiCOM P24x range, which Schneider Electric presents for rotating machines and medium and large induction and synchronous motors, including high-inertia machines. Both groups are found on medium-voltage motors of pumps, compressors, fans, mills and conveyors in mining, oil, cement, water and power plant auxiliary services.
For the general context, see motor protection relay and induction motor and its protection.
Variants: P220, P225, P241, P242 and P243
| Model | Application | Main difference |
|---|---|---|
| MiCOM P220 | Motors and overcurrent | P22x range; 30 TE format with standard display |
| MiCOM P225 | Motors and overcurrent | P22x range; functions depend on the order code |
| MiCOM P241 | Induction and synchronous motors | Motor management of the P24x range |
| MiCOM P242 | Motors with more field signals | Same as the P241 with more digital inputs and outputs |
| MiCOM P243 | Large motors | Adds motor differential (87) and extended operator control |
On some regional Schneider Electric pages, the P22x range is listed as soon to be discontinued; the P24x range appears as current. Before ordering a spare, confirm availability with the manufacturer.
Main functions
According to Schneider Electric’s public information for the P24x range:
| Function | ANSI | What it adds for the motor |
|---|---|---|
| Optimized thermal image | 49 | Overload and repeated starts (guide) |
| Locked rotor and start supervision | 51LR, 48 | Failed or overly long start |
| Loss of load and undercurrent | 37 | Pump running dry or broken coupling |
| Negative sequence | 46 | Unbalance that heats the rotor (guide) |
| Loss of field and loss of synchronism (synchronous motors) | 40, 78 | Excitation problems (guide) |
| Motor differential (P243) | 87M | Internal fault in large motors (guide) |
| RTD temperature (optional) | 49, 38 | Windings and bearings |
The P24x range includes programmable scheme logic and user-programmable curves, with Schneider Electric’s curve tool to create them and load them into the device.
Communications and integration
Schneider Electric states that the P241, P242 and P243 have serial and Ethernet communication with IEC 61850 Edition 1 and Edition 2 in the same device (selected by setting). They also have PRP and HSR redundancy, dual IP address and universal IRIG-B input. Their cybersecurity functions follow IEC 62351, with role-based access control. The P22x are integrated through their communication port with the protocols of their order code; in old panels it is common to bring them to the SCADA over Modbus or IEC 60870-5-103 through a gateway. Both ranges are configured with Easergy Studio (formerly MiCOM S1 Studio).
What Schneider’s page says about the P22x range
Schneider Electric’s product page presents the P22x range as motor and overcurrent protection relays, with a complete set of functions based on current, voltage and temperature measurements, and lists only the P220 and P225 models. Among the features it highlights are:
- a true RMS thermal image, which also protects against heating from harmonic components;
- busbar voltage verification before starting;
- trip circuit continuity supervision and breaker failure protection;
- functions for high-inertia loads and anti-backspin, which prevent restarting the motor before the rotor stops;
- presentation in rack and compact formats.
Schneider offers a standard two-year warranty. From the same page it links the product documentation, the software downloads, the product selector and the substitution and replacement table. That table is the starting point to know which current device the manufacturer proposes. The technical manual of the range (P22x/EN M, software version 11.A or later in the copies in circulation) is the one that defines the function of each cell; verify that it matches your version.
How motor protection thinks
A motor relay does not protect only against high current. The functions of the P22x and P24x ranges answer three different questions, and the guides on the site treat them separately:
- Is the winding heating up? The thermal image integrates the real current, including negative-sequence and harmonic current, and models cooling; see 49 overload trips in motors and RTD protection 38 and 49.
- Did it start properly? The start is supervised by time and by current: a long start or a locked rotor is distinguished from an overload while running; see locked rotor 51LR and 48 and starting large motors and voltage drop.
- Is there an electrical fault? Short circuit, ground fault and phase unbalance or loss of a phase; see 46 trips in motors and loss of load and low current.
The reference standard for these applications is IEEE C37.96, the guide for AC motor protection, which explains the relationship between thermal curve, starting time and locked-rotor time. The settings of each motor depend on its nameplate data and on the manufacturer, not on typical values.
Points of attention in commissioning and maintenance
- Motor data: rated current, starting current and time, locked-rotor time cold and hot and the CT ratio must come from the data sheet and the motor tests; see medium-voltage motor testing.
- Restart after a trip: anti-backspin and restart inhibit depend on the load (pumps with a water column, fans and mills take time to stop); coordinate with the process before shortening times.
- Trip circuit: continuity supervision is only useful if the alarm contact reaches the SCADA; see trip circuit supervision.
- Spare: consult the manufacturer’s substitution table before buying a unit to replace one of the P22x range.
Frequently asked technical questions
- MiCOM P225 manual: the manual depends on the software version; one from another version may show different cells.
- Thermal image trip on starting: the thermal constants and the starting time must come from the motor and load data, not from default values.
- Blocked restarts: the start inhibit protects the hot motor; shortening it without judgment reduces the life of the winding.
- P243 differential that operates on starting: ratios, polarities or saturation of the current transformers on the two sides of the winding.
- Easergy Studio does not recognize the device: the data model for that version is missing or the address and port do not match.
If your device is no longer manufactured
If your P220 or P225 is discontinued, the replacement is not a matter of copying settings: the functions, the inputs and outputs, the communications and the case format change. We review the motor data and the study, design the change, configure the new device and test it before start-up; see engineering design and studies.
How we help
At Tiza Group we configure and review MiCOM motor relays remotely, worldwide, from the motor data and the approved settings, with a backup before and after the change. See remote configuration of Schneider Easergy and MiCOM relays. If a motor tripped and it is not clear why, send us the event through trip analysis, or write to us through the contact page.
Related guides
- Motor protection relay
- Induction motor and its protection
- Motor differential protection 87M
- Thermal overload protection 49
- SEL-710 relay
- Schneider Easergy Studio, Easergy Pro and SFT2841 software
- SEL-849 relay
- Multilin 869 and 859 relays
References
- IEEE C37.2, device function numbers for power systems.
- IEEE C37.96, guide for AC motor protection.
- Schneider Electric, Easergy MiCOM P24x range page and MiCOM P220 product page.
Frequently asked questions
What is the MiCOM P225 relay used for?
It is a relay of Schneider Electric's MiCOM P22x range for motor and overcurrent protection. It is used on medium-voltage motors in industrial plants, with functions based on the motor thermal image and start supervision. The exact functions depend on the order code.
What is the difference between the MiCOM P241, P242 and P243?
According to Schneider Electric, the P241 is a motor management relay, the P242 adds digital inputs and outputs and the P243 adds motor differential protection (87) and a more complete operator control.
Where do I find the MiCOM P225 manual?
Schneider Electric publishes the manuals of the P22x and P24x ranges on its documentation portal, by software version. The manual must match the device version; configuration is done with Easergy Studio, formerly MiCOM S1 Studio.