McQuay MicroTech - User Manual

The MicroTech Open Protocol Master (OPM) Panel is a microprocessor-based controller designed to integrate two or more MicroTech unit or auxiliary controllers into a third-party Building Automation System (BAS). It serves as a single-point connection for communication between the BAS and the MicroTech network.

Function Description:

The OPM Panel acts as a passive communications link, facilitating the monitoring of status and the modification of limited control parameters in McQuay International HVAC equipment by a BAS. It does not perform supervisory control; all such control (e.g., scheduling, overrides, chiller sequencing) is handled by the BAS. The OPM Panel is particularly useful when multiple MicroTech controllers need to be interfaced with a BAS via a single connection, such as combining a centrifugal chiller, an applied rooftop unit, and several unit ventilators into one network.

The OPM Panel allows the BAS to perform several supervisory functions for MicroTech unit and auxiliary controllers, including:

Setting the operating mode.
Monitoring most controller inputs, outputs, setpoints, parameters, and alarms.
Setting most controller setpoints and parameters.
Clearing alarms.

Important Technical Specifications:

Controller Type: Microprocessor-based controller.
Main Component: Microprocessor Control Board (MCB) with hex switches, communication ports, LEDs, and a 1.5-amp fuse.
Power Supply: 115 Vac, sized to carry at least 5 amps.
Internal Protection: 0.5-amp circuit breaker (CB1).
Enclosure: NEMA 1.
Communication Ports:
- Port A: For communications with the BAS using either RS-232C or RS-485. Also used for PC connection during commissioning and troubleshooting (default 9600 baud). Remote connection via modem is not supported.
- Port B: For MicroTech network communications using RS-485 (9600 baud).
Network Architecture: The OPM Panel typically functions as the level-1 controller in an Open Protocol network, with unit controllers as level-2. Series-100 (old style) centrifugal chillers may have a level-2 display processor and a level-3 unit controller.
Network Cable Specification: Twisted, shielded pair with drain wire, 300 V, 60°C, 20 AWG, polyethylene insulated, with a PVC outer jacket (Belden 8762 or equivalent). Maximum allowable length of a communications trunk is 5000 feet.
PC Connection Cable Specification: Twisted, shielded pair with drain wire, 300 V, 60°C, 20 AWG, polyethylene insulated, with a PVC outer jacket (Belden 8762 or equivalent). Maximum allowable length for direct connection between PC and controller is 50 feet.
Environmental Specifications:
- Operating Temperature: 32–100°F (0–37°C).
- Storage Temperature: -40–140°F (-40–60°C).
- Relative Humidity: 0–95%, noncondensing for both operating and storage.
Physical Dimensions: Approximately 14-3/4 inches (375 mm) high, 14-1/2 inches (368 mm) wide, and 4 inches (102 mm) deep. Weighs approximately 30 pounds (14 kg).
Software ID: OPM01B (OPM Panel, Version 01, Revision B).

Usage Features:

Indoor Use Only: The OPM Panel is designed for indoor installations.
Easy Mounting: Four 1/4-inch (6 mm) mounting slots are provided for wall mounting with screws or bolts.
Door Friction Adjustment: Special door hinges with a friction adjustment screw prevent the door from swinging unexpectedly.
Network Addressing: Each controller in the MicroTech network requires a unique network address, consisting of L2 and L3 hexadecimal digits. The OPM Panel (level-1 controller) always has a hex switch setting of 00 (address 00.00). Level-2 controllers start at 01 and continue consecutively.
Commissioning: Requires a PC equipped with Open Protocol Monitor software for setup and network diagnostics. The PC connects to Port A of the OPM Panel.
Safety Features: Equipped with a push-button circuit breaker (CB1) for overcurrent protection and as an on-off switch. High and low voltage sections are separated by a sheet metal barrier.

Maintenance Features:

LED Diagnostics: Green and red LEDs on the MCB provide status information for troubleshooting.
- Red LED On (longer than 5 seconds): Indicates self-test failure or power supply problem.
- Red LED Off, Green LED Flashing: Normal operation.
- All LEDs Off: Defective component or power distribution problem.
Power Problem Troubleshooting: Procedures involve checking CB1, MCB power connector voltages (9-12 Vac between terminals), and the MCB input fuse (F1).
Communications Problem Troubleshooting: Involves checking Port B voltages, network wiring integrity, and network addressing. The "Network Commissioning" section provides detailed start-up procedures for these checks.
MCB Replacement: If the MCB is defective, a replacement board can be ordered. The correct controller software must be loaded onto the replacement MCB, either at the factory or on-site using Open Protocol Monitor software.
Documentation: The manual includes a wiring diagram and a parts list for easy reference during service.

Safety Warnings:

Electric Shock Hazard: Equipment must be properly grounded. Connections and service must be performed by knowledgeable personnel. All protective deadfront panels must be reinstalled and secured after wiring.
Static Sensitive Components: Discharge static electrical charge by touching bare metal inside the control panel before service. Do not unplug cables, circuit board terminal blocks, or power plugs while power is applied.
Wiring Compliance: Wiring must comply with the National Electrical Code and all local codes. Warranty is void if wiring instructions are not followed.
Conduit Separation: Do not install communication cables in the same conduit with power wiring.