Binary Inputs-Main Control Board (Mcb); Binary Inputs-Auxiliary Control Boards (Ccb1 And Ccb2) - McQuay MicroTech II Installation And Maintenance Manual

Binary Inputs-Main Control Board (MCB)

The 16 binary inputs to the MCB are in the form of 0 VAC
(off) or 24 VAC (on) applied to the binary input terminals.
Transformer T2 is the source of the 24 VAC for these inputs.
Table 10: Binary Inputs for Main Control Board (MCB)
Binary Input
MCB-BI1 External Time Clock or Tenant Override
MCB-BI2 Manual System Disable
MCB-BI3 Remote Cool Enable
MCB-BI4
Remote Heat Enable
MCB-BI5 Heat Failure Alarm
MCB-BI6 Airflow Status
MCB-BI7 Freeze Alarm for Steam, Hot Water Coils, or Waterside Economizer
MCB-BI8 Smoke Alarm
MCB-BI9 Filter Switch
MCB-BI10 Not Used
MCB-BI11
Outdoor Enthalpy Status
MCB-BI12 Not Used
MCB-BI13 Not Used
MCB-BI14
Duct Hi Limit
MCB-BI15 Not Used
MCB-BI16 Water Flow Switch
a. Not used on 100% outdoor air units.
b. Applicable on VAV units only.
Binary Inputs-Auxiliary Control Boards
(CCB1 and CCB2)
The optional auxiliary control boards include 12 binary
inputs. Inputs BI1 through BI6 are designed for a set of dry
contacts between the COM terminal and the individual
binary input terminals on J9. BI7 through BI12 are designed
for 24 VAC inputs (input is ON when 24 VAC is present at
the corresponding input terminal on J10 and OFF when
0 VAC is not present). The following sections describe how
these inputs are defined for each of the auxiliary control
boards.
Note: The set of jumpers in the upper right corner of the
board (under the N2 Communications Card) must
IM710
Input Description
a
b
Each binary input has an LED associated with it that lights
when 24 VAC is present at the corresponding input terminal.
These binary input LEDs are grouped together and are
located in the upper left hand corner of the board. Table 10
summarizes the binary input functions and LED indications
for the binary inputs to the MCB.
both be in the "down" position (jumper on the bot-
tom two pins). Placing the jumper in the "up" posi-
tion (jumper on the top two pins) internally
interlocks binary inputs BO1 with BI1 and BO2
with BI2 respectively. This interlock is not used on
this product application
CCB1 & CCB2
Cooling Circuit #1 through Circuit #4 are controlled by the
CCB1 and circuit #5 and #6 are controlled by the CCB2.
Table 11 and Table 12 on page 24 summarize the binary
inputs for the CCB1 and CCB2 respectively.
Lit LED Indication
Occupied
Disabled
Enabled
Enabled
Alarm
Airflow Detected
Normal
Normal
Normal
-
Low OA Enthalpy
-
-
Normal
-
Normal
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