DISASSEMBLY OF PQM200

SURGE PROTECTION DEVICE

CREATED BY C R U Z , J A I M E E

D O B B S , M I C H A E L

G U Z M A N , F R A N K

O G U N D E R E , A D E B O W A L E

W A L L A C E , R I C H A R D

Reverse Engineering Project EEL 4906 Engineering Design/Professionalism

September 30th , 2014

OUR PROJECT OBJECTIVE IS TO ULTIMATELY CONVERT A STATIC SURGE SUPPRESSION DEVICE INTO ONE WITH

INTELLIGENCE (AND BETTER PERFORMANCE CHARACTERISTICS AMONG

OTHER ENHANCEMENTS) THAT WILL RECORD DATA AND TRANSFER THAT DATA

VIA WI -FI TO A LOCAL AREA NETWORK FOR MONITORING PURPOSES.

INTRODUCTION

INTRODUCTION CONTINUED

PQM200 is a Surge Protection Device (SPD) designed to provide protection to service panels, load centers or where the SPD is directly connected to the electronic device requiring protection.

The following sections of this presentation will describe at a component level those parts that are significant to the operation of the device.

Simplified System Wiring Block Diagram

Metal-Oxide Varistor (MOV)

A varistor, also known as a Voltage-Dependent Resistor is an electrical device with a non-linear current/voltage characteristics.

Varistors are used as a control/protection device to suppress line voltage surges from other sensitive devices.

Fail Indicator

This red tab is the fail indicator, indicating to the user that the Varistor has degraded completely and needs to be replaced.

Printed Circuit Board

The PCB includes a proprietary overvoltage sensing circuit.

Essentially, all circuitry and pathways for signally circuits reside on the PCB. The pictures below identify the PCB as a significant part for the operation of the SPD.

Housing, Display & Leads

The housing encloses all the components together in one compact unit. The inside has rail slots on it that allow the removable tray to slide in and out.

The display is on the top of the housing.

The leads plug into the back of the housing and are 10 AWG wires

Modular Tray and Fuses

The Module Tray is the main feature of this SPD that makes it standout from all others. The design of the tray allows for easy removal and replacement of any of the modules it sits, if one were to be defective.

The fuses serve as a redundant protection measure for the SPD. If the circuit breaker feeding power to the device were to fail, the fuses are there as back up.

Cost Analysis

a) Metal-Oxide Varistor ~ $95.00

b) Printed Circuit Board ~ $85.00

c) Housing ~ $65.00

d) Modular Tray ~ $50.00

e) Fusing ~$40.00

f) Connection Leads ~$40.00

TOTAL ~$360.00

Block Diagram of Initial Design

Conclusion

The reverse engineering exercise of this surge protection device was crucial to comprehending how the device works.

This has, in turn, allowed us to focus on the exact connection points for the new MOV degradation sensing circuitry and monitoring points in order to adapt Wi-Fi for the reporting of the MOV degradation.

The modular tray and housing was extensively examined so that we can devise a mechanical solution for tool-less entry into the device, and to figure out physical modifications to accommodate all of the enhancements into the device.

[ 1 ] P O W E R L O G I C S , I . ( N . D . ) . P Q P R O T E C T I O N S U R G E P R O T E C T I O N D E V I C E S . R E T R I E V E D 0 9 2 5 , 2 0 1 4 , F R O M P O W E R L O G I C S , I N C : H T T P : / / W W W . P Q P R O T E C T I O N . C O M / P D F / P Q M 2 0 0 _ S U R G E _ P R O T E C T I O N _ D E V I C E .P D F [ 2 ] E P C O S . ( 2 0 1 2 , 0 4 0 9 ) . P O W E R G U R U – P O W E R E L E C T R O N I C S I N F O R M A T I O N P O R T A . R E T R I E V E D 0 9 2 5 , 2 0 1 4 , F R O M P O W E R G U R U : H T T P : / / W W W . P O W E R G U R U . O R G / O V E R - V O L T A G E - P R O T E C T I O N - U S I N G - V A R I S T O R S [ 3 ] L I T T L E F U S E . ( N . D . ) . P R O D U C T S - V A R I S T O R S . R E T R I E V E D 0 9 2 5 , 2 0 1 4 , F R O M L I T T L E F U S E : H T T P : / / W W W . L I T T E L F U S E . C O M / V A R I S T O R [ 4 ] C I T E L , I . ( 2 0 1 3 , 1 1 ) . S U R G E P R O T E C T I O N 9 T H E D I T I O N . R E T R I E V E D 0 9 2 5 , 2 0 1 4 , F R O M C I T E L : H T T P : / / W W W . C I T E L . F R / F L I P B O O K / G E N E R A L _ C A T A L O G _ C I T E L _ 9 E D _ N O V E M B E R 20 1 3 _ 2 . P D F [ 5 ] V I C F U S E . ( N . D . ) . C L A S S O F F U S E S . R E T R I E V E D 0 9 2 5 , 2 0 1 4 , F R O M V I C F U S E : H T T P : / / W W W . V I C F U S E . C O M / A S P _ B I N / P R O / 1 3 7 2 5 5 7 0 8 0 . P D F S P E C I A L T H A N K S T O O U R C O R P O R A T E P A R T N E R P O W E R L O G I C S , T H E S U R G E P R O T E C T I O N S O L U T I O N F O R Y O U R C R I T I C A L E Q U I P M E N T .

REFERENCES