MS3 Series Jockey
Pump Controllers
MS3 Series
Jockey Pump Controllers
The MS3 Jockey (or make-up) Pump Controllers
are in the same system as the main fire pump
controller(s). Their purpose is to maintain normal
water pressure and to help prevent unnecessary
cycling of the main fire pump(s).
The MS3 series Jockey Pump Controllers are
listed to UL 508 Standard for Industrial Controls.
Each controller contains an externally operable
fused disconnect switch with fuses which are
horsepower rated, motor contactors with
protective overload relay, and a door mounted
hand-off-auto switch all housed in a NEMA 2 drip
proof enclosure. As an option, a circuit breaker is
available in lieu of the fused disconnect
The MS3 Jockey Pump Controllers include a
pressure switch with independent high and low
set points for automatic starting and stopping.
The pressure switch is piped to an external 1/4
inch NPT connector.
Standard features of the MS3
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MS3 Jockey Pump Controller
Externally operable disconnect
Horsepower rated fuses
Hand-Off-Auto selector switch
Pressure switch
Control power transformer
Minimum run period timer
NEMA 2 enclosure
Wye-Delta Open Transition Starting
Bulletin MS3 02/09 vØ