SZJB50A-D Normally Closed DC Contactor

The importance of normally closed DC contactors goes beyond their individual applications; they play a vital role in wider electrical control systems. In industrial environments where machines and equipment are in continuous operation, the reliability of switchgear is critical. Normally closed DC contactors help improve the overall efficiency and safety of these systems, ensuring that power is managed effectively.

product details

FEATURES

In commercial environments, the use of normally closed DC contactors can enhance energy management. By automatically controlling power to individual systems, businesses can reduce energy consumption and operating costs. This is especially important in industries where energy efficiency is a key concern, such as manufacturing and commercial real estate.

SAYOON MODEL IMPLICATION

SZJB	50A	-D	-□	/□
1	2	3	4	5

1	Product type
2	Rated current
3	Coil type: D-Single coil structure
4	Mounting bracket type: None-M Horizontal (default); E1-Level embedded single direction; L(N)-Vertical
5	Coil rated voltage: 12V, 24V, 36V, 48V, 60V, 72V etc.

Uses

This product have one normally close contact, for electric vehicles, telecommunication equipment, engineering machinery, car batteries, electric forklift trucks, trains, ships, electronic control systems such as uninterruptible power supply.

Technical Parameters: (Version 2.11)

SAYOON Product Type	SZJB50A-D
Contact form	1 NC
Coil Rated voltage (DC V)	6V,12V,24V,36V,48V,60V,72V,84V,120V,150V etc.
Contact voltage (DC V)	≤60V
Rated load current of contact 48V circuit (DC-1)	50A
Rate load current of contact circuit	≯80mV
The cooling pull-in voltage at (20±5)℃ (V)	≯70%
The cooling drop-out voltage at (20±5)℃ (V)	≯35%,≮5%
Working voltage range of 40℃ coil	0.8-1.2Us
Drop-out time (n/o contacts to open)	10ms
Pull-in time (n/o contacts to close)	25ms
Maximum bounce time for contact connection	10ms
Maximum bounce time for contact disconnection	3ms
Insulation resistance	20MΩ
Electric strength to resist	50Hz/60Hz 1000VAC 1minute
Typical fault currents which can be ruptured	600A/5ms at 48V DC
Coil power (W)	7-15
Temperature rise of coil (K)	≤80
Temperature rise on outgoing terminal (K)	≤65
Electrical life	20,000 times
Mechanical life	300,000 times
Work specification	Intermittent
Contact material	Ag alloy
Load terminal type	M5 Screw
Coil terminal type	M4 Screw
Testing organization certification	CCC,CE,FCC,RoHS

Note:As regarding to the different using environments of customers which requires different focus of the functions,and in order to improve the comprehensive properties of our products,sayoon may adjust the coil parameters,temperature rise and so on. The above parameters are for reference only, For details, please refer to the guidelines for selection and use of the SAYOON DC contactor.

Load Characteristic Curve

Installation Diagram

Wiring Diagram

Temperature Curve

Mechanical Ability And Use Of The Environment

Contact lead M6 tightening torque (N.m)	≯4.5 appropriate
Coil lead M4 tightening torque (N.m)	≯1.2 appropriate
Ambient temperature	-25~+70℃
Relative humidity	+20℃ 98%
Vibration freq. atthe fixed position	3G, 1～50Hz amplitude 0.5mm
Concussion	(60～100) time/minute、acceleration≤4g
Altitude	2000m
Installation direction	Random
International Protection	IP40 (According IEC60947)

Order Instruction

SAYOON Product Type	SZJB50A-D
U.N.W.	170g
Package QTY.	100PCS
Mounting bracket type	None - M Horizontal (default), E1 Level embedded single direction, L (N) Vertical

When ordering, please state the following: name, full model, control coil voltage specification, installation frame type, whether with auxiliary contact, order quantity. For example: DC Contactor SZJB50A-D/24V 100pcs, indicating the load rated current 50A, without auxiliary contact, default mounting bracket, coil control voltage 24V purchase 100pcs. Special voltage specification products, such as user needs can be special order.