- for -

F.M. Approvals- by -

James S. Nasby

Columbia Engineering

Motor Drive Controller Functions and Operation

C.E. F.M. Approvals 2

Topics Covered Type of Controller

Manual Combined Automatic

Measurement Timing Remote Functions

C.E. F.M. Approvals 3

Type of Controller Manual Only Controller

Peerless "Mantrol" was U.L. Listed Most F.P. Engine Panels do this

Automatic Controller Must be both A Manual Controller -and- An Automatic Controller

C.E. F.M. Approvals 4

Timing Cranking Delayed Starting: Which Demands?

Sequence Start: Static Demands• Pressure (Weekly Test)• Deluge• A.C. PF Start

Don’t Delay• Remote Momentary Switch (Push Button)

High Zone Start - Which Demands Static Demands -and- Remote Momentary (Don't Want to Start a Dry or

Cavitating Pump)

C.E. F.M. Approvals 5

Non-Standard Functions Start Timing

Sequential (Parallel Pumps)• Which Demands are Delayed?

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

Lockout - When OK?

C.E. F.M. Approvals 6

Additional Functions Breaker Test Switch Re-Start Delay Avoids Re-closing Contactor with Motor

Back EMF present Will almost Always be Out of Phase 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 Single Phase Protection Shunt Trip

A.C. Powered = 1/3 Odds of Tripping D.C. Powered = Better Odds Triple Redundant CPTs & D.C. Powered = Best Odds of

Tripping.

C.E. F.M. Approvals 7

A Very Large Military SiteVariable Speed Motor, Engine and Jockey Pump

C.E. F.M. Approvals 8

Voltage Margins Low Line Performance

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

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

Affect on Function Metering

*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. F.M. Approvals 9

Questions?