Zoning circulator controller

• US 5,466,995 A
• Filed: 09/29/1993
• Issued: 11/14/1995
• Est. Priority Date: 09/29/1993
• Status: Expired due to Term

• Current Assignee: Taco, Inc.
• Original Assignee: Taco, Inc.
• Inventors: Genga, Richard A.
• Primary Examiner(s): Martin, David S.
• Application Number:
  US08/128,831
• Time in Patent Office: 776 Days
• Field of Search: 237/8 R, 237/8 A, 237/8 B, 237/8, 237/C, 237/8 D, 417/410.1, 417/422, 417/42-45, 318/3, 318/432-434, 318/778-788, 318/798-816, 388/903, 388/904
• US Class Current: 318/3
• CPC Class Codes: F04D 13/0606 Canned motor pumps
• CPC Class Codes: F04D 15/0022 throttling valves or valves varying the pump inlet opening or the outlet opening
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: F04D 15/0077 Safety measures F04D15/02 takes precedence
• CPC Class Codes: H02K 17/30 Structural association of asynchronous induction motors with auxiliary electric devices influencing the characteristics of the motor or controlling the motor, e.g. with impedances or switches
• CPC Class Codes: H02K 5/128 using air-gap sleeves or air-gap discs

Abstract

A zoning circulator for circulating fluid within a zone in a hydronic heating or cooling system includes a zoning circulator controller including a speed regulating circuit for controlling the speed of a circulator motor. The circulator controller also includes an override circuit for operating the circulator at a high speed, high starting torque for several seconds to overcome frictional resistances between the moving parts of the motor and then tapers down to the speed established by the speed regulating circuit.

Claims

1. A zoning circulator for circulating fluid within a hydronic heating or cooling system, the zoning circulator comprising:

a wet-rotor circulator motor, the circulator motor comprising;

a motor housing,

a stator disposed within the motor housing and sealed from the circulating fluid,

a rotor housing disposed within the motor housing within the stator, the rotor housing being unsealed from the circulating fluid so that the fluid enters the rotor housing,

a rotor disposed within the rotor housing and in contact with the fluid, and

an impeller affixed to one end of the rotor, the stator and rotor configured with respect to one another so that the rotor is caused to rotate when the stator is energized;

an impeller casing fastened to the motor housing, the impeller casing including an inlet end for accepting the circulating fluid flowing into the impeller casing, an impeller zone into which the impeller extends from the motor, the impeller zone being in fluid communication with the inlet of the impeller casing, and an outlet end for discharging the circulating fluid flowing from the impeller casing, and

a circulator controller physically attached to the circulator motor and including a speed regulating circuit for providing electrical drive signals to the motor to operate the motor, the speed regulating circuit controlling a rate at which the electrical drive signals are provided to the motor, the rate being representative of a preselected speed across a range of speed settings between a predetermined minimum speed setting and a predetermined maximum speed setting, wherein the speed regulating circuit operates the circulator motor for a predetermined initial period at a speed setting sufficient to generate a torque to overcome frictional resistances in the circulator motor and thereafter operates the circulator motor at the preselected speed setting of the speed regulating circuit.

2. The zoning circulator of claim 1 wherein the speed setting generating the torque sufficient for overcoming frictional resistances in the circulator motor is the predetermined maximum speed setting.

3. The zoning circulator of claim 1 wherein the circulator controller further comprises an electrical switch connected to the circulator motor and the speed regulating circuit, the switch, including at least one low voltage activation terminal and at least one pair of high voltage switched terminals for receiving a high voltage supply signal, the electrical switch being configured to switch the high voltage switched terminals when low voltage is supplied to the activation terminals.

4. The zoning circulator of claim 3 wherein the electrical switch is a solid-state AC switching device.

5. The zoning circulator of claim 1 wherein the speed regulating circuit comprises an override circuit including a resistor and capacitor network and the predetermined duration of operation of the override circuit is related to the values of the resistor and capacitor.

15. The zoning circulator of claim 1 wherein the circulator controller further includes a controller housing integral with the circulator motor, the speed regulating circuit located within the housing.

6. A zoning circulator for circulating fluid within a hydronic heating or cooling system, the zoning circulator comprising:

a circulator motor;

a circulator controller physically attached to the circulator motor, the circulator controller comprising,

a voltage transforming device for receiving and transforming a high voltage supply signal to a low voltage,

an electrical relay connected to the transforming device, including at least one low voltage activation input terminal and at least one pair of high voltage switched output terminals for receiving the high voltage supply signal, the relay being configured to switch the output terminals when low voltage from the transforming device is supplied to the activation input terminals,

an electrical switch, connected between the electrical relay and the circulator motor, having at least one low voltage activation input terminal and at least one pair of high voltage switched output terminals for receiving the high voltage supply signal from the electrical relay, the electrical switch being configured to switch the output terminals when low voltage is supplied to the activation input terminals,

a speed regulating circuit connected between the electrical switching device and the circulator motor for controlling the speed of the circulator motor and for providing low voltage signals to the at least one low voltage activation input terminal of the electrical switch to control a rate at which the high voltage supply signal at the at least one pair of high voltage switched output terminals are provided to the motor, the rate being representative of a preselected speed within at a preselected speed across a range of speed settings between a predetermined minimum speed setting and a predetermined maximum speed setting, and

an override circuit connected to the electrical switch for overriding the speed regulating circuit upon initial application of the high voltage supply signal to operate for a predetermined duration the circulator motor at a speed setting sufficient to generate a torque to overcome frictional resistances in the circulator motor, the speed regulating circuit thereafter operating the circulator motor at the preselected speed setting.

7. The zoning circulator of claim 6 wherein the speed regulating circuit is manually controlled to operate at the preselected speed setting.

8. The zoning circulator of claim 6 wherein the zoning circulator further includes a minimum speed control device to establish a minimum speed setting of operation for the circulator motor.

9. The integrated zoning circulator of claim 6, wherein the voltage transforming device is a transformer.

10. The zoning circulator of claim 6 wherein the preselected speed setting of the speed regulating circuit varies in response to a varying thermal load of the system.

11. A zoning circulator for circulating fluid within a hydronic heating or cooling system, the zoning circulator comprising:

a circulator motor;

a circulator controller, physically attached to the circulator motor, including an electrical switch, connected to the circulator motor, having at least one low voltage activation input terminal and at least one pair of high voltage switched output terminals for receiving a high voltage supply signal, the electrical switch being configured to switch the output terminals when low voltage is supplied to the activation input terminals, and a speed regulating circuit connected to the electrical switch for operating the circulator motor at a desired speed within a range of speed settings between a predetermined minimum speed setting and a predetermined maximum speed setting, including;

an input circuit for receiving a low level electrical signal from a thermostat and for converting the electrical signal to a voltage signal representative of a desired speed setting of the motor,

a time delay circuit for controlling the rate of switching of the electrical switch based on the voltage signal representative of the desired speed setting of the motor, and

an override circuit connected to the electrical switch for overriding the speed regulating circuit upon initial application of the high voltage supply signal to operate for a predetermined duration the circulator motor at a speed setting sufficient to generate a torque to overcome frictional resistances in the circulator motor, the speed regulating circuit thereafter operating the circulator motor at the desired speed setting.

12. The zoning circulator of claim 11 wherein the low level electrical signal is a current signal between 4 and 20 milliamperes.

13. The zoning circulator of claim 11 wherein the low level electrical signal is a voltage signal between 0 and 10 volts.

14. The zoning circulator of claim 11 wherein the time delay circuit comprises a resistor and capacitor network and the rate of switching is related to the values of the resistor and capacitor.