EOCR-PMZ (panel embedded) and EOCR-PFZ (embedded) motor comprehensive protector

Detecting leakage current through an external zero sequence current transformer (ZCT). Provide two ranges and characteristics:

Time limit (dE): Range 0.03~10A, adjustable delay Et of 0.05~10 seconds.

Inverse Time Limit (Inv): Only applicable within the range of 0.03~1A, following the inverse time limit curve.

In addition, the grounding fault delay Ed (1-10 seconds) during startup can be set separately to avoid false tripping caused by brief leakage current during startup.

2.4 Phase sequence, missing phase, and imbalance

Reverse phase (RP): When enabled, any two phase wiring errors will trip within 0.1~0.3 seconds to protect the safety of mechanical equipment rotation direction.

Phase loss: Detected any phase current loss, action time ≤ 3 seconds.

Unbalance: The calculation formula is (maximum phase current - minimum phase current)/maximum phase current x 100%. When the imbalance rate exceeds the set value (default action of 8 seconds), it can effectively reflect the short circuit between turns of the motor winding or the three-phase voltage imbalance.

2.5 LRT and Stall

Locked rotor protection: During the start-up process, if the current reaches 1.5 to 5 times the overcurrent setting value and the duration exceeds Ot (start-up delay), the protection will be activated.

Stall protection: In the event of mechanical jamming during operation, when the current reaches 2-10 times the overcurrent setting value, it will activate according to the OT time limit.

Parameter Setting and Operation Practice: From Beginner to Proficient

EOCR-PMZ/PFZ adopts five key operation (up, down, SET, reset), and the menu logic is clear. Taking a typical setup process as an example:

3.1 Basic steps

Mode selection: Press the up/down keys to switch to the menu item that needs to be modified (such as current setting oc).

Enter editing: Press SET once, and the displayed value will start flashing.

Adjust value: Press the up/down keys to change the value.

Save: Press SET again and the flashing stops to save.

Exit: Press the reset button or wait for 30 seconds to automatically exit.

3.2 Detailed Explanation of Key Parameters (Based on Etc Extended Menu)

After entering Etc mode, the following advanced functions can be set (some of which repeat the parameters directly set on the front panel, but provide additional options):

Parameter Code Function Description Optional Values and Recommendations

RPR reverse phase protection switch on/off, it is recommended to set it to on

E1c overcurrent characteristics dE (definite time limit)/In (inverse time limit)/th (thermal memory)

E2c grounding fault characteristics dE/In

E2o grounding fault output contact type a (normally open)/b (normally closed)

The 4-20 transmission output full-scale current setting corresponds to a current value of 20mA (e.g. if set to 50, 50A outputs 20mA)

RH operation time reminder set to OFF or 1-9990 hours, alarm upon arrival

The accumulated running time of rt is displayed as read-only and cannot be reset

Ct external CT ratio is set to the primary value of the transformer (e.g. 200/5, set to 200)

Trip fault record query shows the reasons and current of the last three trips

After entering the test self-test function, simulate a trip and verify the external circuit

3.3 Common Setting Traps

Switching between inverse time limit and definite time limit for grounding fault 0.03~1A: If a definite time limit needs to be used within the range of 0.03~1A, it is necessary to first enter Etc and set E2c to In (at this time, the range automatically changes to 0.03~1A), and then return E2c to dE in order to obtain the small current range under the definite time limit.

Undercurrent and overcurrent interlock: Uc setting value must be lower than oc, otherwise it cannot be saved.

Reset mode selection: H-r (manual reset, press panel button), E-r (reset by power off and then power on), A-r (automatic reset, adjustable from 0.3 seconds to 20 minutes). For faults such as phase loss, reverse phase, grounding, and locked rotor, even if set to automatic reset, it will not reset automatically and needs to be manually cleared.

Installation and wiring points: avoid the risk of "burning machine"

4.1 Power supply and output contacts

Power terminal A1/A2: Supports AC/DC 85-250V (50/60Hz) wide voltage input, be sure to confirm the voltage specifications before wiring. The 24V version is ordered separately.

Output contacts: OL (overload) is 2-SPST, OR (ground fault or alarm) is 1-SPST, contact capacity is AC250V/3A resistive load. The default contact state is b (95-96 normally closed, 97-98 normally open), and the a/b mode of the ground fault contact can be changed through parameter E2o.

4.2 Current Transformer and ZCT Wiring

Main circuit core penetration: For EOCR-PMZ (window type), the three-phase wires need to pass through the built-in CT holes. Pay attention to the consistency of current direction. Although EOCR uses average value detection internally, it is recommended to maintain consistent direction to avoid phase to phase interference.

Zero sequence current transformer (ZCT): The matching ZCT (35mm, 80mm, 120mm aperture optional) must be used, and the ZCT secondary line must be connected to the Z1 and Z2 terminals. ZCT secondary side must not be grounded, otherwise it may cause measurement errors and even damage the internal circuit.