Civ servers generally place limits on the numbers of certain blocks that can be placed in a chunk, particularly those related to redstone.

Limits

Block Limit per chunk
HOPPER 16
PISTON_BASE 8
PISTON_STICKY_BASE 8
DISPENSER 16
DROPPER 16
COMPARATOR 12
FURNACE 40
PISTON_EXTENSION 8
PISTON_MOVING_PIECE 8

Command Reference

Command Description
/chunklimits Lists the chunk limits.