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2.3 ELECTRICAL WIRING2.3 ELECTRICAL WIRING
2.3 ELECTRICAL WIRING2.3 ELECTRICAL WIRING
2.3 ELECTRICAL WIRING
2.3.1 Interconnection with other HTST Components
A functional representation of the HTST Differential Pressure Switch, as intercon-
nected with other components of the HTST process is shown in Figure 5. The connec-
tion terminal numbering of 1-5 (shown) corresponds to general industry numbering
standards.
A time delay relay may be placed in series with the JD Booster Pump relay and
Booster Pump starter. The relay reduces the risk of cycling that may occur during
startup of the system. As the system moves toward operating pressure, the Flow
Diversion Valve moves from Divert to Forward flow, rapid pressure changes may
occur. Resulting cycling may cause premature failure of the Booster Pump starter
circuitry. Recommended components are shown below. Both provide adjustable
closure delay of one (1) to ten (10) seconds on a 10 amp secondary capacity.
120 VAC, 50-60 Hz - Use Potter & Brumfield Model CHB-38-70001 or equivalent
240 VAC, 50-60 Hz - Use Potter & Brumfield Model CHB-38-80001 or equivalent
Alternately, the adjustable on-board high pressure limit switch may be utilized to
prevent cycling inherent at startup. The Booster Pump relay is wired in series with the
high pressure limit switch, set to trip just below the normal pasteurized operating
pressure. This will prevent the Booster Pump from starting until normal system back-
pressure is developed, thus eliminating the need for a time delay relay.
If the high pressure limit switch is not being utilized, another typical application is to
prevent freeze up of the cooling section. Most systems will have the pasteurized
sensor placed at the outlet of the regenerating section, and the inlet of the cooling
section. The high pressure limit switch is set to a maximum safe operating value, with
the contacts being wired to the cooling pump. If the high alarm is reached, as in a
freeze up condition, the cooling pump will automatically stop until pressures return to
a safe operating zone.
FIGURE 5 INTERCONNECTIONSFIGURE 5 INTERCONNECTIONS
FIGURE 5 INTERCONNECTIONSFIGURE 5 INTERCONNECTIONS
FIGURE 5 INTERCONNECTIONS
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