Key Circuit Features

• The mains side (primary) can be considered hazardous to any electronics for the purpose of this application. Therefore, no vital control circuits are located on the primary side.
• All monitoring is performed through transformer isolation (secondary side). The same transformer is also supplying the power for the control circuits. To ensure the transformer load is not affecting the measurements, the supply and measurements are synchronised @ 180 degrees apart. Power is supplied on the positive mains cycle and measurements are performed only during negative mains cycles.
• In 3-phase devices, all phases contribute to the power supply of the unit.
• The mains input stage offers MOV (Metal Oxide Varistor) surge attenuation to promote fast disconnects of switching gear.

 

More specifically MACS Monitoring includes:

Normal power up

• or the first ~3seconds the “phase status” lights are both activated showing an “orange” light.
• After, the yellow “Delay On timer” light is activated for the period set by the “Del-On” set point adjuster of 3 minutes. During this period, both relay contacts are open.
• When the “delay timer” has expired, the yellow light is switched off and both relay contacts are switched on.
• The “phase status” confirms the operation with a green “Power Good” light.

Out of tolerance power up

• For the first ~3seconds the “phase indicator” lights are both activated showing an “orange” light.
• If one or more phases are above or below the thresholds set by the “High” and “Low” set point adjusters, the relays remain switched off.
• The “phase status” indicates the fault condition with a red “Protection On” light.
• The amber “phase voltage indicators” assist with fault finding. A dim or no light is a sign for a low or lost phase.

Monitoring

• During monitoring operation, all phases are being measured on a cycle by cycle basis. If okay, the “phase status” confirms the operation with a green “Power Good” light.
• If one or more phases are above or below the thresholds set by the “High 255V” and “Low 205V” set point adjusters, the “Delay-Off” timer is activated in about 0.8 seconds.
• After expiry of the “Delay-Off” timer, the phase conditions are verified. If still exceeding the thresholds, the relays are switched off.
• The “phase status” indicates the condition with a red “Protection On” light.
• When the phase voltages are back within the set thresholds, the yellow “Delay-On timer” light is activated for the period set by the “Del-On” set point adjuster to around 3 minutes.
• During this period, both relay contacts remain switched off (open).
• When the “delay timer” has expired, the yellow light is switched off and both relay contacts are switched on.
• The “phase status” confirms the operation with a green “Power Good” light. If there are no lights indicating on the PCB, you have complete loss of power also known as a Black Out.

USB Diagnostics

Port MACS Monitoring can also connect to a PC USB port. It is intended to be used as a temporary connection only while commissioning, servicing and extracting data logs.

Note: OTG devices such as tablets and phones are currently not supported.

(For best protection at the switchboard, a surge diverter would also improve greater protection against surges in line with the MACS Monitoring device which you can ask your qualified electrician about).