RISH Lay

The Protector Trip Relay Series

Data Sheet
Motor Protection Relay

www.rishabh.co.in Page 1 of 3 Version : 1 / 03 / 0611 / A

Models available Specifications
Nominal frequency : 50 Hz ± 3%
System Voltage : 110, 220, 230, 240,
Function / System Type 380, 415 VAC ± 20%
Motor Protection Relay 253 - MPR Aux Supply : 110, 220, 230, 240,
(Phase Loss, Reversal, Unbalanced) 380, 415VAC ± 20%
Burden : 3VA
Voltage withstand : 1.2 x rating continuously
Applications
1.5 x rating for 10 sec.
• Portable pumps To BS - 6253
• Portable compressors Unbalance Trip : 30 to 70 V ± 9 V
• Motor driven mixing equipment Setting

• Motors Set Accuracy : ± 10% of Set value

• Gensets - correct engine rotation Time Delay : 3.5 Sec. ± 1.5 Sec.
Reset : Automatic, Manual,
• All portable motorised equipment
Remote
• All rotating machines Test : Can be simulated
for working without
Features connecting the inputs
• Phase Sequence Test Time Delay : 3.5 Sec. ± 1.5 Sec.
• Phase Loss Output Relay Type : D.P. Changeover
• Adjustable unbalance Voltage Contact Rating A.C. : 240V, 5A
• Testing simulation D.C. 24V 5A resistive
• Automatic, manual & remote reset available Operations : 0.5 million at 100 %
• LED trip indication and Power ON loads
• 2 pole relay contacts Indication : L1 - Power ON
L2 - Trip
• Polycarbonate casing (UL 94 V-0)
Enclosure : Polycarbonate
• Protective clear terminal cover (UL 94 V-0) (UL 94 V-0)
Dimensions (mm) :
Introduction Overall 75 x 70 x 112
Mounting 35 x 55
The Rishabh Protector is designed to monitor the correct
phase rotation or sequence of 3 phase system R, Y, B. Weight : 400 gms. approx.
Rotating machines are particularly vulnerable to incorrect
phase sequence. Three Phase motors rotate in the wrong
direction, potentially leading to physical damage or the risk of
injury to personel, yet voltage & current reading may appear
Product function
normal. If one phase is lost because of a blown fuse, electric MPR is a phase failure relay operating on negative sequence
motors can continue to operate (single phase) which can result voltage sensing principle. It offers protection against.
in severe electrical or mechanical damage.
For permanent installation, this relay should be used to monitor • Phase sequence reversal condition.
the incoming supply, protecting all equipment against incorrect
connection at initial installation or after maintenance work. • Phase failure condition.
Rotating machines that cannot tolerate reverse rotation or • Unbalanced voltage condition
pose significant risk to personel under this condition should be
individually protected with this relay. The possibility of incorrect MPR is an auxiliary relay and it should be used along with the motor
supply connection is much more likely in portable equipment or starter only. The effective working of MPR will depend on efficient
marine applications. working of electromagnetic motor starter. Before installing MPR check
whether the motor starter is operating perfectly by starting the motor
with "START" push button and switching it off by "OFF" push button. If
Applicable Standards motor does not "START" or "STOP" on respective operations, the
starter needs to be serviced. Do not install MPR with faulty motor
: BS 60255, starter.
Applicable Standard
IS 3231-1997 Trip Setting:
Relay can be set to trip the starter for any unbalance voltage between
Safety Requirements : BS 5458, IEC 414 30 V to 70 V + 9V between any two phases.
Temperature Range : 00 C to 600 C Time Delay:
MPR offers sufficient Trip time delay of 3 - 4 Sec. for all, Phase
Storage Temperature : 200 C to 700 C Sequence, Phase Loss and Phase unbalance conditions, to prevent
nuisance tripping and hence protects motor.
Temp. Co-efficient : 0.05% per 0C
Enclosure Code : IP50 to BS5490,
IEC 259

www.rishabh.co.in Page 2 of 3 Version : 1 / 03 / 0611 / A

Reset: Test & Reset
The relay can be set in Auto reset or manual & remote reset mode by If the relay is to be tested without connecting it in the control circuit of
removing or putting a short link between terminal 11 & 12. Relay can be motor, then connect the required aux input (indication LED L1 should be
remotely reset by extending the remote reset push button provided on ON), check the o/p relay contacts at 13 and 14. Press TEST button.
terminal 10 & 11 (Use continuous cable at max. distance of 100 meters) Then RESET the relay either by pressing RESET button or shorting pin
no 10 & 11, the relay will be energized. If these operations are
Relay will reset if unbalance voltage is reduced to less than 20 V between
satisfactory then relay is working properly and can be used with load.
all three phases.

Electrical Connection Connection diagram

Remote
reset PB
AUX A/M link
R Y B
R
Y
MOTOR 1 2 3 7 8 10 11 12
B
PROTECTOR MOTOR PROTECTION RELAY

OFF AUX SUPPLY VAC RISHABH

50
N/V 14 RESET 40 60
TEST
1 R 13
DOL STARTER 15
17 30 70
16
18 L2 L1
3 B Y
ON 1 2 3 7 8 10 11 12
AUX
LINK IF STARTER DOES NOT HOLD INTERCHANGE 1 & 3
SUPPLY
2
13 14 15 16 17 18
10 11 12
Contact Set 1 Contact Set 2
A / M LINK 13 14 15 16 17 18
Terminal Details:
1-2-3 : R-Y-B Phase voltage Input
NOTE : RELAY CONTACT SHOWN FOR UNIT IN HEALTHY CONDITION
7-8 : Auxiliary supply voltage (as marked on label)
10-11 : External Remote Reset push Button.
11-12 : External Link for Automatic / manual, Remote Reset
13-14-15 : Two change over outputs
16-17-18 : Relay contacts (C-NO-NC)
Dimensions
B
112.5
A
Model 253

50

60
70
35

2 FIXING HOLE ‘A’ 2 FIXING HOLE ‘B’

RELEASE CLIP
TO SUIT M4 TO SUIT M5

Ordering Information
Please quote :
1. Product Type. 5. System Voltage and/or Current where applicable.
2. Function i.e. Under or Over. 6. System Frequency.
3. Relays normally de - energise on under trip and energise 7. Auxiliary Voltage where required.
on over trip. 8. Preset Differential where required.
4. Please specify standard or non standard trip. An nergised 9. Time delay where applicable.
relay is indicated by a “Lit” red LED. Setpoint can be
factory adjusted to your requirements.