Ratings; Toc Functions - GE DIAC 66K Instruction Manual

2 PRODUCT DESCRIPTION
Table 2–2: RATINGS OF TARGET AND SEAL-IN COIL
CURRENT
OPERATED
2
Carry 30 amps for
Carry 10 amps for
Carry continuously
Minimum operating
Minimum dropout
DC resistance
60 hertz impedance
50 hertz impedance
The TOC function operates on an 'RMS' current calculated from the sampled values. The IOC function oper-
ates on the sampled values, and the algorithm virtually eliminates the decaying DC offset component to
achieve low transient overreach of less than 7%.
The relays contain two independent settings: one for TOC and one for IOC. These two settings control the
TOC/Instantaneous function of Stud 10. The TOC/Instantaneous units operate in series with each other as in
the Application Diagram shown in Figure 5–3: TYPICAL EXTERNAL CONNNECTIONS FOR MOTOR PRO-
TECTION on page 5–4.
The TOC function provides 16 selectable time current curves:
• IAC51
• IAC53
• 55-SHORT TIME
• 57-MEDIUM TIME
• 66-LONG TIME (DIAC Type 66K)
• 75-SHORT TIME
• IAC77
• 95-SHORT TIME
The IAC51, IAC53, and IAC77 curves match the time current curve of the respective IAC model. This includes
the 0.5 through 9.9 time dial setting for the 1 and 5 A units. Numbered curves 55, 57, 66, 75, and 95 match the
shape of the respective IAC model; however, the time dial positions are not one-to-one equivalents. The IEC,
2
IEEE, and I t curves are based on the equations listed with the corresponding curves on pages 2–11 to 2–18.
t curve has a K value equal to the time dial times 250. The minimum value of K is 25 (0.1 × 250) and the
2
The I
maximum value is 2475 (9.9 × 250).
NOTE: IEC equations are defined by IEC 255-4 and IEEE equations are defined by IEEE PC37.112
2-
2
UNITS DUAL-RATED AMP
0.2 AMP TAP
(seconds) 0.05
(seconds) 0.45
(amperes) 0.37
(amperes) 0.2
(amperes) 0.05
(ohms) 8.3
(ohms) 50
(ohms) 42
• IEC Inverse
• IEC Very Inverse
• IEC Extremely Inverse
• IEEE Inverse
• IEEE Very Inverse
• IEEE Extremely Inverse
• Definite Time
• I
DIAC Type 66K Digital Overcurrent Relay
2.0 AMP TAP
2.2
2.0
2.3
2.0
0.5
0.24
0.65
0.54
2
T
GEK-106261

2.3 RATINGS

2.4 TOC FUNCTIONS

GE Power Management