Main Control Board (Mcb) Output Relays And Triacs; Auxiliary Control Boards (Ccb1And Ccb2) Output Relays; Keypad/Display - McQuay MicroTech II Installation And Maintenance Manual

Binary Outputs Terminal Block
The auxiliary control board includes nine binary output
relays (BO1 through BO9) that are energized based on com-
mands received from the MCB. These relays provide the
appropriate switching actions for the control devices that are
wired to them through the BO terminals on the left side of
the board. Refer to "Binary Outputs-Auxiliary Control
Boards (CCB1 and CCB2)" on page 27 for details regarding
binary outputs.
N2 Communications Card
Each auxiliary control board is equipped with a plug in N2
Communication Card. This card includes a 3 position termi-
nal block with terminals labeled N2
terminals are wired to the "Plus", "Minus" and REF termi-
nals on the N2 communication terminal block on the MCB.
The auxiliary control board exchanges information with the
MCB via this interface.
Each auxiliary board N2 Communication Card includes an
8-position dip switch assembly (SW1) for addressing the
board. Refer to Figure 4 on page 10. CCB1 must always be
set to address 2 and CCB2 to address 3. This is done by set-
ting the switches on each of the auxiliary control boards as
indicated in Table 4. If the switches are not set as indicated,
the MCB will not communicate correctly with the board and
the auxiliary control board will not function properly.
Table 4: Auxiliary Control Board Address Switches
Auxiliary
Control
Board
1 2 3
(Address)
CCB1 (2)
Up Down Up
CCB2 (3) Down Down Up
Power Supply Terminals (J1)
Transformer T3 supplies 24 VAC power to terminal block
J1, terminals 1 (24VAC) and 2 (COM) on the auxiliary con-
trol board (CCB1 and CCB2).
J7 Terminal Block
The J7 terminal block located at the top of the auxiliary con-
trol board is not used in this product application.
J2 Terminal Block
The J2 terminal block located between the J10 and J8 termi-
nal block on the right side of the auxiliary control board is
not used in this product application.
Main Control Board (MCB) Output Relays
and Triacs
Binary outputs BO1 through BO4, BO11 and BO12 control
pilot duty Form C electromechanical relays mounted on the
IM710
+
, N2- and REF. These
Dip Switch #
4 5 6 7 8
Up Up Up Up Up
Up Up Up Up Up
the MCB. The output terminals of these relays are connected
to a set of binary output terminal blocks located on the right
side of the MCB. These relays are designed for Class 2 oper-
ation and to switch loads with any of the following charac-
teristics:
5VDC @ 10 mA minimum, 1 A maximum
30 VAC @ 2 A nominal, 10 A inrush
Binary outputs BO5 through BO10 and BO13 through BO16
control triacs mounted on the MCB. The output terminals of
these triacs are connected to a binary output terminal block
located on the right side of MCB. These triacs are designed
to switch loads with any of the following characteristics:
30 mA minimum, 24 VAC @ 1 A maximum
Auxiliary Control Boards (CCB1 and
CCB2) Output Relays
Binary outputs BO1 and BO2 control high power Form A
electromechanical relays mounted on the auxiliary control
board. The output terminals of these relays are connected to
the binary output terminals located on the left side of the aux-
iliary control board. These relays are designed to switch
loads with any of the following characteristics:
1 hp 120 VAC
25 A resistive @ 120 VAC
Binary outputs BO3 and BO9 control low power Form A
electromechanical relays mounted on the auxiliary control
board. The output terminals of these relays are connected to
the binary output terminals located on the left side of the aux-
iliary control board. These relays are designed to switch
loads with any of the following characteristics:
1/10 hp 120 VAC
5 A resistive @ 120 VAC
Binary output BO6 controls one low power Form C electro-
mechanical relay mounted on the auxiliary control board.
The output terminals of this relay are connected to the binary
output terminals located on the left side of the auxiliary con-
trol board. This relay is designed to switch loads with any of
the following characteristics:
1/10 hp 120 VAC
5 A resistive @ 120 VAC

Keypad/Display

The keypad/display, shown in Figure 5 on page 12, has eight
keys and a 4 line by 20 character LCD display. The key-
pad/display is the operator interface to the MCB. All operat-
ing conditions, system alarms, control parameters, and
schedules can be monitored from the keypad/display. If the
correct password has been entered, adjustable parameters or
schedules can be modified. For information on using the
keypad/display refer to the "Getting Started" section of the
applicable operation manual (Refer to Table 1 on page 3).
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