- for -

IEEE-IAS- by -

James S. Nasby

Columbia Engineering

Motor Drive Controller Functions and Operation

C.E. IEEE-IAS 2

Topics Covered Type of Controller

Manual Combined Automatic & Manual

Measurement Timing Remote Functions

C.E. IEEE-IAS 3

Type of Controller Manual Only Diesel Controller

Peerless "Mantrol" (Historic) Most F.P. Engine Panels also do this.

Automatic Controller Must be both A Manual Controller -and- An Automatic Controller Applies to both Diesel and Electric Drive

Controllers

C.E. IEEE-IAS 4

Optional Functions Start Timing

Sequential (Parallel Pumps)•Which Demands are Delayed?

High Zone Delay (Pumps in Series)•Which Demands are Delayed?

Lockout - When OK? Redundant pumps Dual Drives (Historic) Other by AHJ Permission

C.E. IEEE-IAS 5

Ideal Optional Timing Operation

Sequence Start: Static Demands ONLY (Normally Closed Loop)

• Pressure (Weekly Test)• Deluge• A.C. PF Start (Diesel Controllers)

Should NOT Delay (Normally Open Circuit)• Remote Momentary Switch (Push Button)

Ideal Controllers Provide Both N.C. & N.O. Inputs High Zone Start Delay: All Demands

Static Demands -and- Remote Momentary (Don't Start or Cavitate a Dry

Pump)

C.E. IEEE-IAS 6

Potential Total Delay Stack-up:High Rise Building on Loss of Normal Power

1) 3 to 10 Second Delay Gen-Set Start Signal2) 10 Seconds for Gen-Set to Provide Power & Xfer Switch to

Transfer3) 10 Seconds Controller Boot-up Time, if Applicable (Some

were almost a Full Minute.)3) High Zone Delay on Upper (Protect in Place) Zone: 10 + 10

Seconds (For Low Zone and Mid Zone Pumps to Start)4) 10 Seconds Max. Accelerate Time.5) Can You Hold Your Breath for 60 Seconds?6) A Fire Heat Plume can Fuse (Open) Many Sprinkler Heads

in this amount of time. This could overload the pump.7) Better Controllers: 3 + 10 + 0 + (5 + 5) + 3 = 26 Seconds.

Far Better.

C.E. IEEE-IAS 7

Important Additional Features Breaker Test Switch - When supplied Re-Start Delay (when supplied) Avoids Re-closing

Contactor with Motor Back EMF present Re-start will likely be Out of Phase (Wye-Delta Open) 3/4 to 1-1/2 Seconds "Open Circuit Magnetic Time

Constant" for Induction Motors. Delay of 2 to 3 Seconds = One or More Time Constants

(63% Drop) to Safe Levels Full Single Phase Start Protection (G.E. started) Phase Reversal Test Switch (Avoids Reprogramming

and Password Problems or Changing Control Wiring)

C.E. IEEE-IAS 8

Important Features - cont'd

Shunt Trip Operation A.C. Powered = 1/3 Odds of Tripping

• E.g.: 2/3 Odds of Not Tripping on a Fault• This Due to A.C. Powered Shunt Trip Coil

Ideal Units hold Calibration During:• Three Phase Over Current (LRA)• Line to Line Fault• Line to Ground Fault

D.C. Powered = Fully & Always Functional Triple Redundant CPTs & D.C. Powered = Best

Odds of Tripping.

C.E. IEEE-IAS 9

Voltage Margins - Motor Controllers Line Voltage Variation Performance Low Line Performance:

During Motor Starting (Weak Source)• 15% Minimum• 35% Far Better

Alternative is Contactor Chattering (100 Hp Door Bell Buzzer) and No Fire Pump Start

High Line: Stand-by - High Line - 110% = Bare Minimum• 480 x 110% = 528*

Line Voltage Affect on Function - Reliability & Trouble Free Service Life Metering - Accuracy Drastically Affected on Some

*Can be Even Higher for Service Entrance Equipment due to Close Proximity to the Building Transformer which might have Taps set to Compensate for Long Wire Runs.

C.E. IEEE-IAS 10

Voltage Margins - Diesel Controllers

Low A.C. Line Performance Battery Charger Electronics

High Line Performance Charger Heating

Low D.C. Voltage Operation - (Breakaway and Cranking)

High D.C. Voltage - Heating

C.E. IEEE-IAS 11

Questions?