The coil should not be energized without being assembled on operator. All GEM-SOL coils are designed to operate at + or - 10% of normal voltage. GEM-SOL coils are capable of operating at 100% ED, however when energizing AC8W or DC10W coils for a long time, the temperature attained may affect solenoid seals. For outdoor applications or when the coil is exposed to high humidity, we recommend the use of impregnated coils.