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Protector trip relay - Crompton Instruments - 250 Series - AC Voltage with Adjustable Time Delay
Features
- Adjustable set point
- Adjustable time delay
- Internal differential
- LED trip indication
- Double-pole relay contacts
- Automatic reset
Benefits
- Over and under-voltage monitoring
- Close voltage control
- Start standby generators
- Operation of mains failure units
- Switching standby supplies
- Protecting computer supplies
- Monitors genset AVR and excitation systems
- Nuisance tripping avoidance
- Customised options
Applications
- Switchgear
- Distribution systems
- Generator sets
- Control panels
- Process control
- Motor protection
- Transformers
- Overload protection
Operation
AC voltage protectors offer user adjustable trip point (set point) and time delay settings. The set point adjustment range is 25%, operating between 75% and 100% of the nominal supply for under-voltage units and between 100% and 125% for the over-voltage units. The time delay setting adjustment range is typically 0 to 10 seconds, although longer delays are available. As soon as the monitored signal moves outside of the set point limit, the time delay is activated, after which a trip will occur. The time delay prevents the relay from tripping for a predetermined period to prevent nuisance tripping.
The products also feature an internal differential (hysteresis) setting of 1% to reduce nuisance tripping if the measured signal is noisy or unstable. The units draw their operating power from the measuring inputs, although a separate auxiliary supply input option is available on some models. Single-phase and three-phase products are available. Three-phase products monitor the voltage level for each phase and are not phase sequence sensitive.
Over-Voltage Models
When the monitored voltage exceeds the set point, the time delay is started. When the time has elapsed, the relay will energise and the red LED will illuminate to indicate the trip condition. The relay will automatically reset once the monitored
voltage falls below the set point minus the differential. When reset, the LED will extinguish and the relay de-energises. The time delay is not active when resetting.
Under-Voltage Models
When the monitored voltage falls below the set point, the time delay is started. When the time has elapsed, the relay will de-energise and the red LED will extinguish to indicate the trip condition. The relay will automatically reset once the monitored voltage rises above the set point plus the differential. When reset, the LED will illuminate and the relay energises. The time delay is not active when resetting.
Options
250 series protector relays offer various customised options to suit individual requirements. Please consult factory.
- Adjustment ranges – different adjustment ranges are possible for the set point and differential controls.
- Separate auxiliary supply – sometimes required to maintain a time delay.
- Differential – internally fixed value between 1% and 15%.
- Relay operation – standard models are fail safe, but the relays can be customised to energise or de-energise on trip.
Product Codes
Relay |
Protection |
ANSI no. |
Cat. no. |
1-phase |
Under-voltage 75-100% |
27 |
252-PVZ |
1-phase |
Over-voltage 100-125% |
59 |
252-PVH |
3-phase 3-wire |
Under-voltage 75-100% |
27 |
252-PVJ |
3-phase 3-wire |
Over-voltage 100-125% |
59 |
252-PVC |
3-phase 4-wire |
Under-voltage 75-100% |
27 |
252-PVX |
3-phase 4-wire |
Over-voltage 100-125% |
59 |
252-PVS |
Specification – AC Voltage with Adjustable Time Delay
Nominal voltage |
100V, 110V, 208V, 240V, 277V, 400V, 415V, 440V or 480V |
System frequency |
45/65Hz or 360/440Hz |
Voltage burden |
0.3VA |
Overload |
1.2 x rating continuously, 1.5 x rating for 10 x seconds |
Set point repeatability |
>0.5% of full span |
Differential (hysteresis) |
Pre-set at 1%. Other values 1% to 10% to order |
Trip level adjustment |
Under-voltage: 75 to 100%; Over-voltage: 100 to 125% of nominal input voltage |
Time delay |
Adjustable up to 10 seconds |
AC auxiliary supply voltage |
100V, 110V, 120V, 208V, 220V, 240V, 480V, ±20% |
DC auxiliary supply voltage |
12V, 24V, 48V, 110V or 125V, ±20%. Including ripple |
Auxiliary voltage burden |
4VA (max) |
Output relay |
2-pole change over |
Relay contact rating |
AC: 240V 5A, non inductive. DC: 24V 5A resistive |
Relay mechanical life |
0.2 million operations at rated loads |
Relay reset |
Automatic |
Operating temperature |
0°C to +60°C (0°C to +40°C for UL models) |
Storage temperature |
–20°C to +70°C |
Temperature co-efficient |
0.05% per °C |
Interference immunity |
Electrical stress surge withstand and non-function to ANSI/IEEE C37 90a |
Enclosure style |
DIN-rail with wall mounting facility |
Material |
Flame retardant polycarbonate/ABS |
Enclosure integrity |
IP50 |
Dimensions |
55mm (2.2") wide x 70mm (2.8") high x 112mm (4.4") deep |
Weight |
0.4Kg approx. |
Connections
252-PVZ
252-PVH
252-PVX
252-PVS
252-PVC
252-PVJ
Note: The neutral connection is always used on four-wire systems.
Dimensions
Model 252
Danh mục sản phẩm
System |
Protection |
Catalog Number |
AC Voltage (Adjustable time delay 0-10 sec., fixed hysteresis 1%) |
Single Phase L-N |
Under Voltage 75-100% |
252-PVZU-PQBX-C6-EB-T1 |
Single Phase L-N |
Over Voltage 100-12% |
252-PVHU-PQBX-C6-EA-T1 |
3 Phase, 3 Wire L-L |
Under Voltage 75-100% |
252-PVJU-PQBX-C6-EB-T1 |
3 Phase, 3 Wire L-L |
Over Voltage 100-12% |
252-PVCU-PQBX-C6-EA-T1 |
3 Phase, 4 Wire L-N |
Under Voltage 75-100% |
252-PVXU-PQBX-C6-EB-T1 |
3 Phase, 4 Wire L-N |
Over Voltage 100-12% |
252-PVSU-PQBX-C6-EA-T1 |