Brookfield Bath, Model TC-101 - Manual (Page 7)

2.6 Open Bath Circulation
The DUPLEX pump permits circulation to and from an open bath. Position both baths so that the two fluid
levels are at the same elevation. If not, siphoning will occur when the unit is turned off. To prevent this, drain
both hoses (pressure and suction). Use the same diameter and length of tubing and type of fittings on both
the inlet and outlet connections to obtain a balanced flow. When using flexible tubing, the suction tubing must
have a wall thickness that will not collapse when under vacuum, especially when going around bends. Cut the
external bath end of the suction tube into a “V” shape so the end of the tube will not seal itself against the
external bath tank wall and overflow the bath. The DUPLEX pump is very powerful. Firmly fasten the tubes to
the external tank wall so they will not move when in use.
Prevent baths from over filling each other by introducing a small amount of air into the pump. There are two
methods, internal and external bath height regulation:
Internal bath height regulation - Fill the external bath to the desired level. Set the tubes into the external bath
fluid without touching the bottom of the tank. The internal bath fluid height is controlled at two inches below
the level of the reservoir cover.
External bath height regulation - Fasten the inlet and outlet tubes at the desired maximum fluid level in the
external bath. The flow must be regulated by use of an adjustable clamp or valve on the outlet side of the
pump so that there is greater suction than pressure. Fill the internal bath to one inch below the top of the
reservoir and adjust the pump outlet flow restriction so that the levels in each bath remain the same.
2.7 Closed Loop Circulation
The DUPLEX pump can also be used in closed loop circulation. Connect the pump inlet and outlet to your
application. Use care to avoid restrictions in the tubing in order to maintain adequate flow. When connecting
to more than five closed loops we recommend use of a manifold made of “Y” adapters to divide the fluid into
two or more banks. A booster pump may be added without damage to the circulation bath pump. After setting
up multiple closed loops, check that there is adequate flow at the return manifold for each loop and recheck
bath fluid level.
The control stability of a closed loop system will generally be better at the external apparatus than in the
immediate vicinity of the heater, provided the apparatus control point represents a constant load and is well
insulated For example, if you circulate at 50°C through a viscometer, the temperature variation observed in the
reservoir may be +0.05°C, whereas in the viscometer it may be only +0.02°C. Although temperature stability
may be better at the external apparatus, the temperature accuracy at the external location may be affected by
flow rate, tubing length, and insulation.
2.8 Power Supply
Plug the unit into a properly wired, grounded outlet with the same voltage and frequency indicated on the
identification label on the back of the unit. With the Power switch OFF, the display should respond by showing
“STANDBY”. Be sure the circuit breaker at the rear of the controller is in the ON position. Use of an extension
cord is not recommended, but if necessary, use one that is properly grounded and will handle the total
wattage of the unit. The extension cord must not cause more than a 10% voltage drop to the circulator.
Firmware Versions
Each unit contains internal programming called firmware. These programs are occasionally updated and are
identified by single letters A through Z. When turning on unit, observe the display. There will be a lower case
letter “v” followed by a capital letter indicating firmware version.
NOTE: This information is important when calling for service.
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