Inverter controller, method of operation thereof and field-installable retrofit kit incorporating the same

Patent metadata

Field	Value
Publication number	US-9677797-B2
Application number	US-201113327475-A
Country	US
Kind code	B2
Filing date	Dec 15, 2011
Priority date	Dec 15, 2011
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

An inverter controller, a method of operating a controller and a field-installable kit. In one embodiment, the controller includes: (1) a thermostat interface configured to receive conventional thermostat signals providing for a ventilation mode, first- and second-stage cooling modes and at least one heating mode and provide relay control signals for an inverter forward start relay, first- and second-stage cooling speed select relays and at least one heating relay and (2) an inverter controller coupled to the thermostat interface and configured to receive the relay control signals and provide an inverter forward start signal, an inverter high speed set, an inverter medium speed set and an inverter ventilation speed set.

First claim

What is claimed is:

1. A field-installable adapter for a heating, ventilation and air conditioning (HVAC) controller of an HVAC system having a blower and a compressor, comprising:
a thermostat interface configured to receive conventional thermostat signals providing for a ventilation mode, first- and second-stage cooling modes, a free cooling mode that employs outside air to cool indoor space, and at least one heating mode, and provide relay control signals for an inverter forward start relay, first- and second-stage cooling speed select relays, a free cooling relay, and at least one heating relay based on the conventional thermostat signals, wherein the inverter forward start relay, first- and second-stage cooling speed select relays, the free cooling relay, and the at least one heating relay energizes the compressor;
an inverter controller coupled to the thermostat interface and configured to:
receive the relay control signals;
when the free cooling relay is activated, activate inverter speed settings for controlling the blower to a high-speed blower operation by employing the relay control signals, the inverter speed settings further includes an inverter forward start signal, an inverter high speed set, an inverter medium speed set and an inverter ventilation speed set; and

a field-configurable blower speed selector, coupled to the inverter controller and a damper, and configured to control the damper to operate as a two-position damper when the blower is a dual-speed blower.

2. The field-installable adapter as recited in claim 1 wherein the thermostat interface is further configured to provide relay control signals for first- and second-stage heating modes.

3. The field-installable adapter as recited in claim 1 wherein the thermostat interface is further configured to provide an inverter 24 VDC output.

4. The field-installable adapter as recited in claim 1 wherein the thermostat interface is further configured to receive a free cooling signal from an economizer, wherein the free cooling signal is based on a comparison of the enthalpy of outside air and inside air.

5. The field-installable adapter as recited in claim 1 wherein the field-configurable blower speed selector configured to select between a single-speed blower and a dual-speed blower.

6. The field-installable adapter as recited in claim 5 wherein the field-configurable blower speed selector controls the damper to operate as a one-position damper when the blower is a single-speed blower.

7. The field-installable adapter as recited in claim 1 wherein the inverter controller is further configured to activate inverter speed settings for switching the blower to a higher speed of blower operation when the relay control signals concurrently give a cooling command and a heating command.

8. A method of converting a single speed controller into a multi-speed controller for a blower of a heating, ventilation and air conditioning (HVAC) system, the method comprising:
receiving conventional thermostat signals providing for a ventilation mode, first- and second-stage cooling modes, a free cooling mode that employs outside air to cool indoor space, and at least one heating mode;
providing relay control signals for an inverter forward start relay, first- and second-stage cooling speed select relays, a free cooling relay, and at least one heating relay based on the conventional thermostat signals, wherein the inverter forward start relay, first- and second-stage cooling speed select relays, the free cooling relay, and the at least one heating relay energizes a compressor of the HVAC system;
providing inverter speed settings for controlling the blower by employing the relay control signals, wherein:
the inverter speed settings include controlling the blower to a high-speed blower operation by employing the relay control signals when the free cooling relay is activated, the inverter speed settings further includes an inverter forward start signal, an inverter high speed set, an inverter medium speed set and an inverter ventilation speed set; and

controlling a damper to operate as a two-position damper when the blower is a dual-speed blower.

9. The method as recited in claim 8 wherein the providing the relay control signals further comprises providing relay control signals for first- and second-stage heating modes.

10. The method as recited in claim 8 further comprising providing an inverter 24 VDC output.

11. The method as recited in claim 8 further comprising receiving a free cooling signal from an economizer, wherein the free cooling signal is based on a comparison of the enthalpy of outside air and inside air.

12. The method as recited in claim 8 further comprising selecting between a single-speed blower and a dual-speed blower with a field-configurable blower speed selector.

13. The method as recited in claim 8 further comprising controlling the damper to operate as a one-position damper when the blower is a single-speed blower.

14. The method as recited in claim 8 wherein the inverter speed settings include switching the blower to a higher speed of blower operation when the relay control signals concurrently give a cooling command and a heating command.

15. A field-installable retrofit kit for converting a single speed blower of a heating, ventilation and air conditioning (HVAC) system into a multi-speed blower, said retrofit kit comprising:
a thermostat interface configured to receive conventional thermostat signals providing for a ventilation mode, first- and second-stage cooling modes, a free cooling mode that employs outside air to cool indoor space, and at least one heating mode and provide relay control signals, based on the conventional thermostat signals, for an inverter forward start relay, first- and second-stage cooling speed select relays, a free cooling relay, and at least one heating relay, wherein the inverter forward start relay, first- and second-stage cooling speed select relays, the free cooling relay, and the at least one heating relay energizes a compressor of the HVAC system; and
a module having:
an inverter controller coupled to the thermostat interface and configured to:
receive the relay control signals;
when the free cooling relay is activated, provide inverter speed settings wherein the inverter speed settings include controlling the blower to a high-speed blower operation by employing the relay control signals, the inverter speed settings further include an inverter forward start signal, an inverter high speed set, an inverter medium speed set and an inverter ventilation speed set,

a field-configurable blower speed selector coupled to the inverter controller and a damper and configured to:
select between a single-speed blower and a dual-speed blower; and
control the damper to operate as a two-position damper when the blower is a dual-speed blower; and

a plurality of relays configured to receive and employ the relay control signals.

16. The retrofit kit as recited in claim 15 wherein the inverter controller is further configured to provide inverter speed settings to switch the blower to a higher speed of blower operation when the relay control signals concurrently give a cooling command and a heating command.

17. The retrofit kit as recited in claim 15 wherein the thermostat interface is further configured to provide relay control signals for first- and second-stage heating modes.

18. The retrofit kit as recited in claim 15 wherein the thermostat interface is further configured to receive a free cooling signal from an economizer, wherein the free co

Assignees

• Havard Jr Harold Gene
• Perez Eric M
• Jewell Terry D
• Hung Der-Kai
• Lennox Ind Inc

Inventors

• Havard Jr Harold Gene
• Perez Eric M
• Jewell Terry D
• Hung Der-Kai

Classifications

• F24F11/67

  Switching between heating and cooling modes · CPC title

• Y02B30/741

  Cross-Sectional Technologies · mapped topic

• F25B2600/11

  Fan speed control · CPC title

• F24F2011/0064

  Mechanical Engineering · mapped topic

• F25B49/02 Primary

  for compression type machines, plants or systems · CPC title