New product:

Connection diagram

The thermistor specification does notneed wires 43, 46 and 49

External command 2
Temperature
sensor 120 LINE（+）
19Temperature
sensor 2

Motor Protection Relay

Temperature
sensor 3N（‑）

IN1
IN2COMMON
13 14
15V0（+）
V0（ ）35 37414243 44

45

46 47

48

49

36 (empty)

21

CT1

PRS-1SGPT

External command 1

2223

CT2SG

PRS-1S

24

38
39 （‑）
40 （+）

Communication(option)

25
26

CT3

27
2829

ZCT

30RS

2019FGPowersupply(+)N(‑)

TTerminal no.
19 ‒ 2021 ‒ 2223 ‒ 2426 ‒ 2729 ‒ 3035 ‒ 37
13 ‒ 1514 ‒ 1518RST51

52

1Input signal

Terminal no.

Control power
supply: DC 110 V51(+) ‒ 52(‒)
40(+) ‒ 39(‒)
38(SG)

CT for current
detection

234567891011121617(+)(‑)
4–20 mA output

Output4 ‒ 20 mA output
Communication
output (option)

ZCTGPT
External command 1
External command 2

Terminal no.
C
147101641
44
47b25811̶4245
48a369121743
4649

OutputFunctionContact output
Selection 1 RY1 selection function
Selection 2 RY2 selection function
Selection 3 RY3 selection function
Selection 4 RY4 selection function
CPU operating status
Fixed
Temperature measurement circuit 1
Temperature measurement circuit 2
Temperature measurement circuit 3

Safety Notice
Carefully read instruction manual to ensure proper installation,connection, operation, handling and maintenance of the product.

Features of the PRS-1S
Head Office: 6-13-47 Kamihigashi, Hirano-ku, Osaka 547-0002, Japan
Circuit Breaker Division: 6-13-47 Kamihigashi, Hirano-ku, Osaka 547-0002, Japan
TEL+81-6-6791-2763
FAX+81-6-6791-2732
int-sales@terasaki.co.jphttp://www.terasaki.co.jp/JUL. 2019

◦ Uses color graphic LCD◦ Large screen provides high visibility and ease of use◦ High functionality with compact and lightweight design◦ Body is designed with maintenance taken into account, and wires and body are easy to install◦ Protection functions also comply with ANSI◦ Enhanced measurement functions

Pamphlet No. ’19-P71E＊Rating and specifications are subject to change without notice.

◦ Built-in clock function

Catalog No.

’19–P71E

The PRS-1S is an electronic motor protection relay with high functionality that detects variousstates when an AC motor starts and while it is operating. Measurement and monitoring
functions are installed in addition to the basic 3 elements of the motor protection function(overload protection, open-phase protection, and reverse-phase protection).
1. Overload protection function
The protection function is adapted to the motor starting characteristics and the load characteristics.

2. Open-phase protection function“Open phase” is a state in which the motor operated in a single-phase state because the power
wire connected to the motor became disconnected, the connection area was loose, or there was adisconnection inside the motor. Open-phase states can cause motor winding burnout, and detecting
open-phase states can prevent this.

General specifications
Control voltage

DC110V

VA consumption

5VA

Outline dimensions

Width 96 × height 144 × depth 116 (includes terminal area on back side)

Temperature range–10℃～ +55℃

Storage temperature–25℃～ +75℃

Humidity

95% or less, and there must not be any condensation

Based standard

IEC60255		
: Measuring relays and protection equipment
IEC60947-4-1 Part 4: Contactors and Motor-Starters

3. Reverse-phase protection function“Reverse-phase” is a state in which the phase sequence of a motor is connected in reverse and themotor rotates in the reverse direction. This cannot be checked visually in some installation locations, andreverse-phase protection is a function that is essential in order to prevent reverse rotation.

4. Other protection functions

Outline dimensions◦ Maximum starting time detection: Measures the time it takes to return to steady-state operation after
the motor starts. If the set time is exceeded, the protection function activates and prevents the motor
from the operation at high speeds.

9611610290.5【Front view】【Side view】【Back view】

92◦ Unbalanced current protection: Detects unbalanced current, which can cause the motor to heat up andburn out and protects the motor.

144◦ Motor winding temperature monitoring: This function monitors the motor winding temperature. The
temperature sensor signal provided near the winding area is incorporated into the circuit inside therelay, and monitors the temperature (the temperature measurement range is 0-250℃ ).

138◦ Undercurrent protection: Activates when a current decrease is detected in the electrical circuit.
The objective of this protection function is to detect light loads and disconnections.

5. Function that displays and saves the activation information and history◦ Trip and alarm activation: If trip or alarm occurs, the time of occurrence, cause of activation, activation
value, and activation duration are displayed on the screen. The system can save 100 instances each oftrip and alarm activation.
◦ History of phenomena that occurred: The system can save a total of 200 instances of the history of thefollowing phenomena that occurred. These phenomena will be displayed on the screen in chronologicalorder, so it is easy to track detailed information about the phenomena that occurred.
・ Trip activation (time of occurrence / cause of activation)
・ Alarm activation (time of occurrence / cause of activation)
・ Reset operation (time of occurrence / reset operation details)
・ External input (time of occurrence / external input state)

Ordering method

PRS - 1S - □□6. Measurement display function◦ The display screen displays the following measurement values.

・ Phase current ・ Unbalanced current ・ Motor winding temperature ・ Motor load current
・ Leakage current ・ Motor starting time ・ Motor starting current ・ Motor operating time・ Motor operating cycles ・ External command input state ・ External output operating state

7. Monitoring function◦ Communication function: In Modbus RTU mode (RS-485), it is possible to read and write protection
setting values and output measurement values and histories.

◦ Analog output: The maximum phase current value can be converted to 4-20 mA current and output
externally.

□1

CT rated current : 1A

5

CT rated current : 5ATTemperature sensor thermistor

P

Temperature sensor RTD (PT100)

N

Without communication function

C

With communication function【Panel cut】