ABB CIRCUIT SHIELD 49 Manuale di istruzioni - Pagina 3
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Motor Overcurrent Relay
PLACING 1HE RELAY INTO SERVICE
1. RECEIVING. HANDLING. STORAGE
IB 7.2.1.7-4
Page3
Upon receipt of the relay (when not included as part of a switchboard) examine for shipping damage. If damage or loss is evident file a claim at
once and promptly notify the nearest Asea Brown Boveri office. Use normal care in handling to avoid mechanical damage. Keep clean and
dry.
2. INSTALLATION
Mounting- The outline dimensions and panel drilling and cutout information is given in Fig. 3.
Connections
Internal
connections are shown in Figure 2. Note that the external connections will be different for the 214 series and 414 series
units. Typical external connections are shown in Figure 1.
These relays have metal front panels which are connected through printed circuit board runs and connector wiring to a terminal at the rear
of the relay case. The terminal is marked "G".
In
all applications this terminal should be wired to ground.
FAST-RESET terminals 15 and 16 are provided for use during testing or for special applications. A momentary contact closure will fully
reset the relay overload memory. CAUTION: the overload (49) unit will be inoperative when1..'Ver terminals 15 and 16 are connected;
therefore,
if
a contact is used, it must provide only a momentary closure.
Control power polarity must be observed for relays rated for use on de control. For relays rated for ac control voltage, it is preferred (but not
required) that the grounded end of the supply be connected to terminal 8 and the hot side to tenninal 7.
All units are supplied with an external power resistor mounted on the back of the relay and wired to tenninals 9 and 10. Tilis resistor must be
connected for proper operation.
Ooerating Mode Selector Plug:
An internal RESET SELECT selector plug is provided to choose whether the relay output contacts will either Iatch(HAND reset) or reset
automatically (SELF reset) after the relay has operated. All units are shipped with the contacts set in the self reset mode. If the contacts are set
in the hand reset mode, the output contacts will latch and must be manually reset by depressing the target reset push button located on the front
panel of the relay.
3. SETTINGS
CURRENT PICKUP TAPS
The tap block, located on the upper part of the front panel, is the "pickup" or "ultimate trip setting" for the OVERLOAD (49) unit. The
settings are marked in ct secondary amperes.
By means of the screwdriver VERNIER adjustment next to the tap block, the relay effectively has a continuous range. With the vernier turned
fully counterclockwise, pickup corresponds to the tap setting. As the vernier is turned clockwise, pickup increases, until at the fully clockwise
position, pickup corresponds to the next highest tap value. With the tap pin in the highest position, the vernier also gives additional range
equivalent to one tap position.
The tap pin may be moved with the relay in service. When the pin is pulled out, pickup switches to the maximum tap setting.
OVERLOAD (49 unit)
This is the time-dial setting for the overload unit of the relay. The dial is marked: l, 2, 3, 4, 5. TI1ese marks correspond to the minutes
required for the relay to trip with an applied input current of2 times the pickup setting. The dial is continuously adjustable between l and 5.
Refer to time-current curve 605838 on page 9. The time curves shown are labeled I through
5
corresponding to the dial position.
STALL (51 unit)
This is the time-dial setting for the locked rotor unit of the relay. The 51 unit has its pickup fixed at 3 times the relay tap setting. The ST ALL
dial is marked: 5, 10, 15, 20, 30. These marks correspond to the seconds required for the relay to trip with an input current of 6 times the
relay pickup setting. The dial is continuously adjustable between
5
and 30 seconds. See time-current curve 605837 on page 10.
FAULT (50 unit)
This is the pickup setting for the instantaneous unit of the relay. The dial is marked in multiples of the pickup setting of the relay. For
example: with a tap setting of3.l amperes and the FAULT dial at 8 multiples, the pickup current is 3.1X8 = 24.8 amperes.
The dial is continuously adjustable from 4 to 16 multiples. See time-current curve 605837 on page I 0.