Controller Outputs; Binary Outputs-Main Control Board (Mcb) - McQuay MicroTech II Installation And Maintenance Manual

Controller Outputs

Binary Outputs—Main Control Board
(MCB)
The main control board has 16 binary outputs that provide
unit control in responses to input conditions. Binary outputs
energize on-board electromechanical relays (BO1 through
BO4, BO11 and BO12) or triacs (BO5 through BO10 and
BO13 through BO16). Unit control devices are wired to the
relays and triacs through six output terminal blocks located
on the right side of MCB.
There are three terminals associated with each binary output.
The terminals associated with BO1 are labeled NO, 1, and
NC, the terminals associated with BO2 are labeled NO, 2,
and NC, and so forth. Each binary output has a LED
associated with it that lights when the corresponding output
relay or the triac is turned on.
Each binary output has an output jumper associated with it.
The three jumper positions are: 1-SRC V (jumper on the
bottom two pins), 2-BRD24V (jumper on the top two pins)
or 3-OFFBRD (no jumper). See Figure 12.
Table 13: Binary outputs for main control board (MCB)
Binary Output
BO1 Discharge Air Fan, On/Off
BO2 Outdoor Damper, Open/Closed
BO3 Fan Operation Output Signal
BO4 Alarm Output Signal
BO5 Close Economizer
BO6 Open Economizer
BO7 Close Bypass Valve
BO8 Open Bypass Valve
Close Heating Valve
a
BO9
Electric Heat Stage #1
Open Heating Valve
b
BO10
Electric Heat Stage #2
BO11 Cool Enable
BO12 VAV Box Output Signal
Decrease Discharge Fan Vane Position
BO13
Decrease Discharge Fan AFD Speed
Increase Discharge Fan Vane Position
BO14
Increase Discharge Fan AFD Speed
BO15 Spare
BO16 Spare
a. If the unit is equipped with modulating heat, output BO9 closes the heating valve. If the unit is equipped with electric heat output BO9 stages on Heating Stage #1.
b. If the unit is equipped with modulating heat, output BO10 opens the heating valve. If the unit is equipped with electric heat output BO10 stages on Heating Stage #2.
McQuay IM 710-1
Output Description
Figure 12:Binary output jumper (MCB)
Top
1 - SRC V.
of
MCB
When the jumper is in position 1-SRC V, 24 VAC from the
SRC 1-8 terminal (BO1 through BO8) or the SRC 9-16
terminal (BO9 through BO16) is applied to the numbered
terminal of the associated outputs. In the case of BO1
through BO4, BO11 and BO12, this signal is then delivered
to either the NC terminal when the corresponding output is
off (output relay de-energized) or the NO terminal when the
corresponding output is on (output relay energized). In the
case of BO5 through BO10 and BO13 through BO16, this
signal is then delivered to the NO terminal when the
corresponding output is on (triac energized). Transformer T3
from the MCB furnishes 24 VAC to the SRC 1-8 terminal
and the SRC 9-16 terminal. This jumper configuration is
used when a specific binary output is used to energize a 24
VAC pilot relay in the unit. See Table 13 on page 21 for the
correct jumper position for all the standard binary outputs.
The 3-OFFBRD (no jumper installed) configuration is not
used in this product application.
The 2-BRD24V jumper configuration is not used in this
product application.
Lit LED Indication
Fan On
Open
Fan Op
Normal
Closing
Opening
Closing
Opening
Closing
Heat On
Opening
Heat On
Enabled
Cooling Mode
Decreasing
Decreasing
Increasing
Increasing
-
-
2 - BRD24V 3 - OFFBRD
(Not Used) (Not Used)
Jumper Position
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
1-SRC V
-
-
21