A20B-1000-0480

A20B-1000-0480

A20B-1000-0480智能电动机保护器短路保护的问题

智能电动机保护器具有很多种保护功能，短路保护是其中之一。其主要保护逻辑是根据采集的电流进线分析和计算，当电流超过5倍电机额定电流时，其短路保护出口发出断路器跳闸命令。该跳闸命令是通过断路器的分励线圈来实现的。这个逻辑本身没有问题，问题出在智能电动机保护器和分励线圈的工作电源上。一般情况下，该工作电源从电动机主回路的某一相上取电，当通信控制模式接线图外部发生三相短路时，母线的各相电压会下降，或工作电源所在那一相发生单相接地短路时，该相电压也会下降。当电压下降到小于智能电动机保护器和分励脱扣器的正常工作电压时，智能电动机保护器和分励线圈均无法正常工作，短路保护也无法实现。其实电动机主回路的断路器本身就具备很好的短路保护功能，所以智能电动机保护器设置短路保护必要性不大。

A20B-1000-0480  

Reliance Cardpak 0-49011-6A Driver Module *GOOD PULL*

Reliance Cardpak 0-49011-9 Driver Module *GOOD PULL*

Reliance Cardpak 0-49012-A Relay Module *GOOD PULL*

Reliance Cardpak 0-49017-57 Summing Module *GOOD PULL*

Reliance Cardpak 0-49026-21 Tester Module *GOOD PULL*

Reliance Cardpak 0-49029-2 Trip Module *GOOD USED PULL*

Reliance Cardpak 0-49060-3 Current Ref Mod *GOOD PULL*

Reliance Cardpak 0-49061 Square Wave Generator Module

Allen Bradley 1771-A2B/B 8-Slot I/O Chassis REV K01

Allen Bradley 1771-A2B/B 8-Slot I/O Chassis REV K03

Allen Bradley 1771-IAD AC/DC Input Module *GOOD PULL*

Allen Bradley 1771-IAD/B AC/DC Input Module *GOOD PULL*

Taian K403-M3 T-Verter AC Drive, Rev D, 4KVA/5.2 Amps

Acopian 14PT12 Rack Power Supply 14VDC/12A *NICE*

AutoPatch 1Y-16 A/V Distribution Matrix Switch *NICE*

Lucent P333T Cajun 24-Port Network Switch *NICE*

P/N 108563123 Stackable

GE Fanuc Universal PLC/Controls Simulator *EXCELLENT*

w/ A860-0201-T001 Manual Pulse Generator

Amrel SPS20-60-000 Programmable DC Power Supply 20V/60A

Mitsubishi FX-1PG PGU (Pulse Generator Unit) PLC

Allen Bradley 6160T53 Programmer Ser B *NICE USED UNIT

Hoffman 303610-CSD Special Enclosure #635M0 *NEW IN BOX

30"x36"x10" with 2 access holes. Painted machinery blue

Hoffman A-SE36X30X8NK Screw Cover Pull Box *NEW IN BOX*

36" x 30" x 8" Painted Machinery Gray, No Knock-Outs

Hoffman A19SH6 19" Vented Fixed Shelf #40030 *NEW*

20" x 17-7/8"

Hoffman APWK2315NF Window Kit #23970 *NEW IN BOX*

23" x 15"

Hoffman C-CC425320PNK Pendant Mount Enclosure *NEW*

21" x 18" x 8" CC-4000 CC4000 CCC425320PNK NEMA 12

Hoffman C-CS2STLG Pendant Arm Swivel Tilt *NEW IN BOX*

CCS2STLG

Hoffman C-KBC26605 Keyboard Compartment CKBC26605 *NEW*

24-3/8" x 11-13/16" x 2" (620mm x 300mm x 52mm)

Hoffman C-TKBC Pendant Arm Pivot Mount CTKBC NEW IN BOX

Hoffman C4FP4253SS Front Plate #44309 *NEW IN BOX*

16-3/4" x 20-7/8" (425mm x 530mm)

Hoffman P-19PSH8 P19PSH8 19" Pull Out Shelf *NEW IN BOX

Hoffman QLINE Enclosure with Extension Ring & Cover NEW

12" x 12" x 8" w/QLINE I Bottom Kit Q-3030IBCKCC #15069

Hoffman X-DS7A6R XDS7A6R Solid Door #68280 *NEW IN BOX*

27-9/16" x 23-5/8" (700mm x 600mm)

Hoffman X-PP48 XPP48 Partial Panel #68570 *NEW IN BOX*