KD4125 Thermal-Magnetic Circuit Breakers with Interchangeable Trip Units

Number of Poles	Amperes	Interrupting Capacity	Type of Trip	Terminals
4	125	Standard 600 Vac Rated 35 kAIC at 480 Vac	Interchangeable Adjustable Thermal-Magnetic	Standard

Quick Reference Guide

NEMA/UL 489/CSA Interrupting Capacity Ratings
Circuit Breaker Type	Number of Poles	Interrupting Capacity (kA Symmetrical Amperes)
		Volts AC (50/60 Hz)						Volts DC
		240	277	480		600		250(1)(2)
DK	2, 3	65	—	—		—		10
KDB	2, 3, 4	65	—	35		25		10
KD	2, 3, 4	65	—	35		25		10
HKD, HKDB	2, 3, 4	100	—	65		35		22
KDC(4)	2, 3, 4	200	—	100		65		22
CKD	3	65	—	35		25		—
CHKD	3	100	—	65		35		—
IEC 157-1 (P1) Interrupting Capacity Ratings
Circuit Breaker Type	Number of Poles	Interrupting Capacity (kA Symmetrical Amperes)
		Volts AC (50/60 Hz)							Volts DC
		240	380	415	440	500	600		250(2)(3)
DK	2, 3	65	—	—	—	—	—		10
KDB	2, 3, 4	65	40	40	—	—	—		10
KD	2, 3, 4	65	40	40	—	—	—		10
HKD, HKDB	2, 3, 4	100	65	65	—	—	—		22
KDC	2, 3, 4	200	100	100	—	—	—		22

NOTES:
(1) Two-pole breaker supplied in three-pole frame. Current carrying parts omitted from center pole.
(2) Two-pole circuit breaker or two outside poles of three-pole circuit breaker.
(3) Time constant is 3 milliseconds minimum at 10 kA and 8 milliseconds minimum at 22 kA.
(4) Current limiting.

310+ Specifications

Trip Unit Type	Digitrip RMS 310+
Breaker Type
Frame	K
Ampere range	250–400A
Continuous current range (A)	55–400A
Ground fault pickup (A)	50–400A
Interrupting capacities at 480 Vac (kAIC)	35, 65, 100
100% rated	Yes
Protection
Ordering options	LS, LSI, LSG, LS(A), LSIG, LSI(A), ALSI, ALSIG, ALSI(A)
Arcflash Reduction Maintenance System	ALSI, ALSIG, ALSI(A)
Interchangeable trip unit	Yes
High load alarm, trip (suffix B20)	Yes
Ground fault alarm, trip (suffix B21)	LSG, LSIG, ALSIG
Zone selective interlock (suffix ZG)	Yes
Cause of trip indication (Catalog Nos: DIGIVIEW, DIGIVIEWR06, TRIP-LED)	Yes
Thru-cover accessories	No

310+ Adjustability Specifications

310+ Settings		K-Frame
		125A	250A	400A
Ir = continuous current or long delay pickup (amperes) (All 310+)	Ir\In
	A (=Ir)	55	100	160
	B (=Ir)	60	125	200
	C (=Ir)	70	150	225
	D (=Ir)	80	160	250
	E (=Ir)	90	175	300
	F (=Ir)	100	200	315
	G (=Ir)	110	225	350
	H (=Ir=In)	125	250	400
tLD = long delay time (seconds) (All 310+)	2	2	2	2
	4	4	4	4
	7	7	7	7
	10	10	10	10
	12	12	12	12
	15	15	15	15
	20	20	20	20
	24	24	24	24
ISD x Ir = short delay pickup (amperes) (All 310+)	Position 1	2	2x	2x
	Position 2	3	3x	3x
	Position 3	4	4x	4x
	Position 4	5	5x	5x
	Position 5	6	6x	6x
	Position 6	7	7x	7x
	Position 7	8	8x	8x
	Position 8	10	10x	10x
	Position 9	12	12x	12x
Ig x In = ground fault pickup (amperes) (310+ w/ground fault)	Position 1	25	50	80
	Position 2	37.5	75	120
	Position 3	50	100	160
	Position 4	75	150	240
	Position 5	100	200	320
	Position 6	125	250	400
Ii x In = instantaneous maintenance mode (amperes) (310+ w/maintenance mode)	Position 1 (2.5x)	312	625	1000
	Position 2 (4x)	312	625	1000
	Position 3 (6x)	312	625	1000
	Position 4	312	625	1000
	Position 5	312	625	1000
	Position 6	312	625	1000
	Position 7	312	625	1000

Note: RMM on KD310+ is not adjustable; it is set at 2.5x.

Specifications

Trip Unit Type	Digitrip OPTIM 550	Digitrip OPTIM 1050
rms sensing	Yes	Yes
Breaker Type
Frame	K	K
Ampere range	125–400A	125–400A
Interrupting rating at 480 volts	35, 65, 100 (kA)	35, 65, 100 (kA)
Protection
Ordering options	LSI, LSI(A), LSIG	LSI(A), LSIG
Fixed rated plug (In)	Yes	Yes
Overtemperature trip	Yes	Yes
Long Delay Protection (L)
Adjustable rating plug (In)	No	No
Long delay pickup	0.4–1.0 x (In)	0.4–1.0 x (In)
Long delay time I2t	2–24 seconds	2–24 seconds
Long delay time I4t	1–5 seconds	1–5 seconds
Long delay thermal memory	Yes	Yes
High load alarm	0.5–1.0 x Ir	0.5–1.0 x Ir
Short Delay Protection (S)
Short delay pickup	150–800% x (Ir)	150–800% x (Ir)
Short delay time I2t	100–500 ms	100–500 ms
Short delay time flat	100–500 ms	100–500 ms
Short delay time zone selective interlocking	Yes(1)	Yes
Instantaneous Protection (I)
Instantaneous pickup	200–800% x (In)	200–800% x (In)
Discriminator	Yes	Yes
Instantaneous override	Yes	Yes
Ground Fault Protection (G)
Ground fault alarm	20–100% x (Is)	20–100% x (Is)
Ground fault pickup	20–100% x (Is)	20–100% x (Is)
Ground fault delay I2t	100–500 ms	100–500 ms
Ground fault delay flat	100–500 ms	100–500 ms
Ground fault zone selective interlocking	Yes(1)	Yes
Ground fault thermal memory	Yes	Yes
System Diagnostics
Status LEDs	Yes	Yes
Cause of trip LEDs	Yes	Yes
Magnitude of trip information	Yes	Yes
Remote signal contact—ground alarm	Yes(1)	Yes
Local auxiliary and bell alarm contact	Optional	Included
System Monitoring
Digital display	Yes(2)	Yes(2)
Current	Yes	Yes
Power and energy	No	Yes
Power quality—harmonics	No	Yes
Power factor	No	Yes
Communications
PowerNet	Yes(3)	Yes
Testing
Testing method	OPTIMizer, BIM, PowerNet	OPTIMizer, BIM, PowerNet

Legend BIM = Breaker Interface Module (A) = GF Alarm Is = Sensor Rating In = Rating Plug Ir = Long Delay Pickup Setting

Notes: (1) Zone interlock kit. (2) By OPTIMizer/BIM. (3) Eaton’s PowerNet kit.

KD4125 Dimensions

Number of Poles	Width	Height	Depth
2, 3	5.50 (149.7)	10.13 (257.3)	4.10 (104.1)
4	7.22 (183.4)	10.13 (257.3)	4.10 (104.1)