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Control relays of ILC™ system in work

I’m an electrical engineer and I have a business of electrical distribution boards (electrical cabinets, electrical panels) production for apartments or cottages. In these types of buildings customers have electrical loads that must work anytime: heat, water and drain pumps, LAN, CCTV cameras, door locks, water drain protection systems and etc.

Some customers have been asking me for an interesting feature: they wanted to have alarm lamp or bell that indicates fault any of important loads because electrical cabinet’s doors are normally closed and customers can’t see tripped circuit breaker immediatelly without opening cabinet’s doors.

Simple solution is adding auxiliary contact for each circuit breaker and monitor status of each breaker by PLC or other controller system like it designed in ABB SMISSLINE bus system. This solution in some reasons is very expensive because I’m often using RCBOs instead of simple circuit breakers: auxiliary contacts for RCBOs is expensive and not all models and brands of RCBO has support for auxiliary contacts.

I designed simple scheme on generic purpose relays and called it Important Lines Control — ILC™. Maybe it should be called «…Check» instead of «…Control», but for a 3 years I’m calling it «…Control» and this naming becomes one of my personal trademarks.

Base idea if ILC™ scheme is adding simple Status Control Relay for each important load and use series connection of their contacts: is all Status Control Relays will be on, we will have «Normal» status of our ILC™ system. If any of Control Relays will be offline — series connection will be broken and we will have «Alarm» status of ILC™ system.

Main advantage of my ILC™ System is it’s hardware realization of all control logic without any PLCs or electronic devices that also may fault. ILC™ System works at simple relays only. Even anyone of relays will be broken — ILC system will give «Alarm» status signal anyway.

I’m using ABB CR-P230AC2 relays with coil for 230V AC voltage. Each relay is connected to output terminals of RCBO or other circuit breaker like shown on scheme below:

ILC™ Scheme: Load control relays part

My scheme is drawn for three-phase power but this design is not canonical: electrical cabinet may have one single-phase power source, two power sources (mains and generator) and etc.

ILC™ Control circuit is protected by separate circuit breaker (it shown as «QF4» at scheme below). Using this breaker we can turn ILC™ System off for electrical cabinet install or setting up procedures (when not all important loads are connected and their circuit breakers must be switched off).

Series connection of ILC™ Control Relays powers ILC™ Status Relay («K4» at scheme below).

Two-way contact of ILC™ Status Relay switching on signal lamp, bell or another indication device that may be installed separate from electrical cabinet (for example electrical cabinet may be installed at basement and ILC™ indication may be installed near main door at first floor of cottage).

ILC™ Scheme: ILC Alarm Status part

Note that «Alarm» signal is connected to a normally closed (NC) contacts if ILC™ Control Relay: when this relay is off, «Alarm» signal must be produced. «Normal» and «Alram» ILC™ signals also connected to cabinet’s external terminals: customer may use these signals for connecting external alarm device outside of electrical cabinet/electrical room.

Additionally (if we have PLC in our cabinet) we can use second contacts of each ILC™ Control Relay to transfer each important load statuses into PLC program through PLC’s digital inputs.

This scheme works very simple: if all ILC™ Control Relays is on — ILC™ Status Relay also will be turned on. If any of loads will be turned off (by tripping circuit breaker or manually) — ILC™ Status Relay will be turned off and normally closed (NC) contacts of this relay will produce «Alarm» signal. Even if coil of any relay will be broken (burned, damaged) — ILC™ Status Relay again will be turned off and again produce «Alarm» signal.

Here is sample of real ILC™ wiring in one of electrical cabinets. Each coil of ILC™ Control Relays is also protected with 0.25A fuse that installed in fulse holder terminal TE M4/8.SF (they’re placed between relays).

Relays that check status of each important load (one relay per each load)

Wire marked «ILCL» («ILC™ Line») makes serial connection of each ILC™ Control relays together. Also you can see wires marked «+24V» (PLC power for digital inputs) and wires marked like «W2.DIx» (PLC digital inputs) that used for check each important load status by PLC individually.

ILC™ System wiring: wire 'ILCL' goes through each ILC Control Relay

Wire marked «ILCL» after all serial connections is connected to «A1» coil contact of ILC™ Status Relay marked «K45» at this cabinet.

Main ILC™ System State relay wiring: wire 'ILCL' comes to 'A1' coil contact

My typical ILC™ Control Panel consists of (components at the right side that not described below is used for another system: thermal protection):

• ILC™ protection circuit breaker (ABB S201 C6) with auxiliary contact that used by PLC to determine that ILC™ System is manually offline: PLC should stop producing individual loads alarm events if all ILC™ System is off;
• Red and Green lamp (ABB E219-2CD) that indicates «Alarm» (Red) and «Normal» (Green) state of ILC™ (lamp is off when ILC™ System is off);
• Bell (ABB RI230) and it switch (ABB E211-16-20). Bell is working when ILC™ is in «Alarm» state, and switch may be used for turning bell off.

ILC™ System control panel. Green lamp indicates normal state

Main ILC™ Status relay is working so we have ILC™ «Normal» state.

Main ILC™ System State relay is on - normal state, no alarms

For example I manually switched off RCBO for one of loads — LAN Cabinet’s power (corresponding ILC™ Status Relay marking is «K37»):

One of the ILC™ control relays in not working: important load turned off due alarm

After that Main ILC™ Status relay immediately switched off too — so we have ILC™ «Alarm» state.

Main ILC™ System State relay is off - alarm state

At ILC™ Control Panel we see red lamp and hear bell.

ILC™ System control panel. Red lamp indicates alarm state

At operator’s panel of PLC we can read two alarm messages. They means: «Important Lines Alarm!» and «Powerdown at LAN Cabinet».

ILC™ System alams showed on operator's panel from PLC

PLC can log this events, transmit it by Modbus TCP/SNMP/MQTT to SCADA or BMS systems.

Проекту исполнилось 15 лет! Поддержать проект материально, проспонсировать проекты Автора или сделать ему подарок можно на этой странице: "Донаты и Спонсорство, Список Желаний".