Analog Inputs Terminal Blocks; Binary Inputs Terminal Blocks; Binary Outputs Terminal Blocks; Rs-485 Communications Terminal Block - McQuay MicroTech II Installation And Maintenance Manual

Analog inputs terminal blocks

The MCB receives up to 16 analog input signals on 4
terminal blocks located on the left side of the board. From
top to bottom, analog inputs AI1 through AI4 are terminated
on the first terminal block, AI5 through AI8 on the second,
AI9 through AI12 on the third, and AI13 through AI16 on
the fourth. Each analog input has two terminals. The
terminals for AI1 are 1 and 1C, the terminals for AI2 are 2
and 2C, and so forth. Refer to "Analog Inputs-Main Control
Board (MCB)" on page 17 for details regarding analog
inputs.

Binary Inputs Terminal Blocks

The MCB receives up to 16 binary input signals on 3
terminal blocks located on the top of the board. From right to
left, binary inputs BI1 through BI6 are terminated on the first
terminal block, BI7 through BI10 on the second and BI11
through BI16 on the third. Refer to "Binary Inputs-Main
Control Board (MCB)" on page 19 for details regarding
binary inputs.

Binary Outputs Terminal Blocks

The MCB controls up to 16 binary outputs when controlling
the unit. The binary outputs either energize on-board
electromechanical relays (BO1 through BO4, BO11 and
BO12) or triacs (BO5 through BO10 and BO13 through
BO16).
The unit control devices are wired to these relays or triacs
through six output terminal blocks on the right side of the
MCB. From top to bottom binary outputs BO1 and BO2 are
terminated on the first terminal block, BO3 and BO4 on the
second, BO5 through BO7 on the third, BO8 through BO10
on the fourth, BO11 through BO13 on the fifth, and BO14
through BO16 on the sixth.
Each binary output has three terminals. The terminals for
BO1 are NO, 1, and NC, the terminals for BO2 are NO, 2,
and NC, and so forth. Each binary output lights an LED
when the output is active. Refer to "Binary Outputs-Main
Control Board (MCB)" on page 19 for details regarding
binary outputs.

RS-485 Communications Terminal Block

The MCB exchanges information with up to four optional
auxiliary control boards via the RS-485 communication bus
terminal block in the lower left corner of the MCB. This
terminal block has four terminals, three of which are labeled
REF, Minus, and Plus. These terminals connect the auxiliary
boards to the RS-485 communication bus to interface them
with the MCB.

Power Supply Terminals

Transformer T2 supplies 24 VAC power to the MCB on the
24V and COM terminals located at the upper right corner of
the MCB.
4
Some of the binary outputs on the MCB drive 24 VAC pilot
relays in the unit control circuit. 24 VAC to power these pilot
relays is provided from transformer T3, through the SRC 1-8
and SRC 9-16 terminals located at the upper right corner of
the MCB, and through the particular binary output contacts.
Note: Place the output jumper associated with these outputs
in the SRC position. For detailed information
regarding binary output jumpers, refer to "Binary
outputs—main control board (MCB)" on page 19.

Keypad/LCD Display Connection

The keypad is connected to the main control board via a six-
conductor cable connected to an RJ-11 style modular jack
located at the bottom of the MCB. This connects the keypad
to the RS-485 communication bus interface with the MCB.

Communication Modules

In systems that require networking, one of the following
communications modules can be installed.

Plug-in BACnet/IP Communications Module

A BACnet/IP Communication Module can be plugged into
the MCB in the port location shown in Figure 2 on page 3.
The BACnet/IP Communication Module is designed to be an
add-on module to the MCB for networking to Building
Automation and Control Network (BACnet) systems. It is a
plug-in module that can be attached to the MCB via a 36-pin
header. It
includes 4 locking stand-offs to securely attach it to the
board. The MicroTech II Vertical Self-Contained Unit
Controller meets the requirements of ANSI/ASHRAE 135-
2001 standard for BACnet/IP per Annex J of the standard
with a conformance level of 3.
For a detailed description and troubleshooting information
regarding this communications module, refer to installation
and maintenance bulletin IM 703, MicroTech II BACnet/IP
Communications Module. For details regarding BACnet
protocol data, refer to engineering data document, ED 15
061, MicroTech II Protocol Information Data for Vertical
Self-Contained Units.
A unit equipped with an optional BACnet/IP
Communication Module is connected to a BACnet/IP
network through an eight-position RJ-45 style modular jack
located on the bottom edge of the MCB. This connection is
shown schematically in Figure 3 on page 6.

Plug-in BACnet MS/TP Communications Module

A BACnet/MSTP Communication Module can be plugged
into the MCB in the port location (see Figure 2 on page 3).
The BACnet MS/TP Communication Module is designed to
be an add-on module to the MCB for networking to Building
Automation and Control Network (BACnet) systems. It is a
plug-in module that can be attached to the MCB via a 12-pin
header, and includes 4 locking stand-offs to securely attach it
to the board. It allows the MCB to inter-operate with systems
that use the BACnet Master Slave Token Passing (MS/TP)
McQuay IM 710-1