ABB COV-11, Instruction

Page 1: ...ncy shutdown of the reactor containment isolation cooling of the reac tor and heat removal from the containment and reac tor or otherwise are essential in preventing significant release of radioactive material to the environment The type COV relay is applicable where it is desired that an overcurrent unit be set to operate on less than full load current when the voltage falls below a prede termine...

Page 2: ...locking nut The bearing can be replaced if necessary without having to remove the magnetic core from the frame The electromagnet has two pairs of voltage coils Each pair of diametrically opposed coils is connected in series In addition one pair is in series with an adjustable resistor These sets are paralleled as shown in Figure 2 The adjustable resistor serves not only to shift the phase angle of...

Page 3: ...NIT CO Since the tap block screws carry operating cur rent be sure that the screws are turned tight In order to avoid opening current transformer cir cuits when changing taps under load start with RED handles FIRST and open all switchblades Chassis operating shorting switches on the case will short the secondary of the current trans former Taps may then be changed with the relay either inside or o...

Page 4: ...ange for the semi flush type FT case The mounting screws may be utilized for grounding the relay External toothed washers are provided for use in the locations shown on the outline and drilling plan to facilitate making a good electrical connection between the relay case its mounting screws and the relay panel Ground wires should be affixed to the mounting screws as required for poorly grounded or...

Page 5: ...op the index mark is offset to the right of the O mark by approximately 020 The placement of the various time dial positions in line with the index mark will give operating times as shown on the respective time current curves For double trip relays the follow on the stationary contacts should be approximately 1 32 B Minimum Trip Current Set the time dial to posi tion 6 Alternately apply tap value ...

Page 6: ...e should not be used until it is apparent that the relay is not in proper working order see Operational Check NOTE A spring shield covers the reset spring of the CO unit To remove the spring shield requires that the damping magnet be removed first The screw connection holding the lead to the moving contact should be removed next The second screw holding the moving contact assem bly should then be ...

Page 7: ... e g COV 8 20 times tap value and measure the operating time Adjust the proper plug until the operating time corresponds to the value in Table 1 Withdraw ing the left hand plug front view increases the operating time and withdrawing the right hand plug front view decreases the time In adjusting the plugs one plug should be screwed in com pletely and the other plug run in or out until the proper op...

Page 8: ...ing position is fixed and cannot be adjusted B The contact gap adjustment for the directional unit is made as follows With the moving contact in the normally closed position i e against the left stop on bridge screw in the stationary contact until both con tacts just close as indicated by a neon lamp in the contact circuit Then screw the stationary contact in toward the moving contact an addi tion...

Page 9: ... 4 37 20 6 20 7 21 0 21 4 23 2 24 9 26 2 103 106 114 122 147 168 180 270 288 325 360 462 548 630 2 6 2 2 5 3 3 5 4 5 6 8 0 8 8 9 7 10 4 11 2 12 5 13 7 230 230 230 230 230 230 230 67 66 64 63 62 59 57 3 88 3 90 3 93 4 09 4 12 4 20 4 38 21 0 21 6 22 1 23 1 23 5 24 8 26 5 110 118 126 136 144 162 183 308 342 381 417 448 540 624 4 12 4 5 6 7 8 10 12 16 0 18 8 19 3 20 8 22 5 25 0 28 0 460 460 460 460 46...

Page 10: ...4 5 6 8 8 8 9 7 10 4 11 2 12 5 13 7 230 230 230 230 230 230 230 66 63 63 63 61 59 58 4 06 4 07 4 14 4 09 4 34 4 40 4 62 21 3 21 8 22 5 23 1 23 8 25 2 27 111 120 129 136 149 163 183 306 342 366 417 448 530 624 4 12 4 5 6 7 8 10 12 16 18 8 19 3 20 8 22 5 25 28 460 460 460 460 460 460 460 64 61 60 58 55 51 46 4 24 4 30 4 62 4 69 4 80 5 20 5 40 22 8 24 2 25 9 27 3 29 8 33 37 5 129 149 168 187 211 260 ...

Page 11: ...nuous Rating Amperes One Second Rating Amperes Power Factor Angle Ø VOLT AMPERES At Tap Value Current At 3 Times Tap Value Current At 10 Times Tap Value Current At 20 Times Tap Value Current 0 5 2 5 0 5 0 6 0 8 1 0 1 5 2 0 2 5 1 7 1 9 2 2 2 5 3 0 3 5 3 8 88 88 88 88 88 88 88 36 34 30 27 22 17 16 0 72 0 75 0 81 0 89 1 13 1 30 1 48 6 54 6 80 7 46 8 30 10 04 11 95 13 95 71 8 75 0 84 0 93 1 115 5 136 ...

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Page 21: ...41 116 1A 21 Figure 11 Outline and Drilling Plan for the Type COV Relay in Type FT21 Case 3519A66 Sub 4 ...