Universal Remote Control MX-880Z - SPECS SHEET Informazioni Techniche Scaricare il pdf (Pagina 48)

™

Masterpact™ NT and NW Universal Power Circuit Breakers

Accessories

05/2014

M2C/M6C Programmable Contact Modules

These contacts are used with the Micrologic P and H control units, and indicate the type of fault and

instantaneous or delayed threshold overruns (i.e trip unit protection pick-up, current/voltage

unbalance, under/over voltage, reverse power, phase rotation, under/over frequency, and load

shedding). The M2C unit is powered from the control unit’s 24 Vdc source (100 mA consumption); the

M6C unit requires an external 24 Vdc power supply (100 mA consumption).

They are programmed via the control unit using a

keypad or via a supervisory station with the COM

communication option. They may be programmed:

•

with instantaneous return to the initial state;

•

without return to the initial state;

•

with return to the initial state following a delay.

Zone-Selective Interlocking (ZSI)

Table 43: Characteristics for M2C/M6C Programmable Contacts

Minimum Load 100 mA/24 V

Breaking Capacity at a Power Factor (p.f.) of 0.7

240 Vac 5 A

380 Vac 3 A

24 Vdc 1.8 A

48 Vdc 1.5 A

125 Vdc 0.4 A

250 Vdc 0.15 A

Zone-selective interlocking (ZSI) is used to

reduce the stress on electrical distribution

equipment during fault conditions by reducing

the time it takes to clear the fault, while

maintaining system coordination between

overcurrent protective devices.

During a short-circuit or ground-fault condition

on a ZSI system, the device directly ahead of

the fault sends a signal upstream via control

wiring to restrain upstream circuit breakers from

tripping and then trips with no intentional time

delay to clear the fault. Upstream devices which

receive a restraint signal obey their short-time

and/or ground-fault delay settings to maintain

coordination in other areas of the system.

Upstream devices that do not receive a restraint

signal trip with no intentional time delay.

For ZSI to work, trip settings must be

coordinated so a downstream circuit breaker will

trip before an upstream circuit breaker under

overload, short-circuit or ground-fault

conditions. (Effective coordination requires a

system coordination study.)

M2C Programmable

Contact Module

M6C Programmable

Contact Module

Fault 1—The upstream circuit breaker (A) will clear the fault

with no intentional delay, regardless of its time-delay setting.

Fault 2—Circuit breaker (B) will inform upstream circuit

breaker (A) that it is clearing the fault. This will prevent circuit

breaker (A) from tripping instantaneously. Circuit breaker (A)

will trip at the end of its time delay setting if the fault is not

cleared during this time.

Example of Zone-Selective Interlocking

1 2 ... 43 44 45 46 47 48 49 50 51 52 53 ... 179 180

Commenti su questo manuale

Nessun commento

Universal Remote Control MX-880Z - SPECS SHEET Informazioni Techniche Pagina 48

Commenti su questo manuale