Quantech QTC40160, Установка, эксплуатация и обслуживание

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Quantech
104
Section 7 - Operation
Form QTC4-NM2
Issue date: 05/12/2023
Basic operating sequence
Start sequence and loading
To initiate the start sequence of the chiller, the
following conditions must be satisfied before the pre-
charge of the DC Bus will take place:
• UNIT SWITCH must be ON.
• At least one System Switch is ON.
• Run permissive inputs (Remote Cycling Contacts)
must be closed.
• No unit faults exist.
• No unit start inhibits exist.
• At least one system not faulted or inhibited.
• The Daily Schedule is calling for the chiller to
run.
• The Flow Switch is closed.
• Leaving Chilled Liquid Setpoint is above the
Setpoint plus CR (Setpoint High Limit).
Once the precharge takes place, if the anti-recycle tim-
er is timed out the chiller control system on the Chiller
Control Board will select the number of compres-
sors to start and begin operation of the compressors.
The compressors speed is ramped to the minimum start
frequency and increase speed as needed in an effort to
regulate the leaving chilled liquid temperature to meet
the required Setpoint.
Microboard (331-03478-xxx)
The 331-03478-xxx microboard uses the IPU3 proces-
sor. The IPU3 processor supports BAS Communica-
tion through the use of the SC-EQ Communications
Card. The IPU3 processor and 03478 board in addition
to the SD also has USB which can be used for software
downloads and data logging.
See
Figure 50 on page 106 to locate the following
ports of the 03478 microboard.
Power supplies and LEDs
The 03478 has LEDs to indicate various states of op-
eration of the microboard.
STATUS – Flashes every 0.5 s to indicate that the base
board processor is running its program.
POWER – On solid indicates that the base board +12
V and +5 V power supplies are operational.
TX1 – Red LED flashes when transmitting data out
Port 1 TB3 (SC-EQ port).
RX1 – Green LED flashes when receiving data in Port
1 TB3.
TX2 – Red LED that flashes when transmitting data
out Port 2 (TB2 or printer TB1).
RX2 –
Green LED that flashes when receiving data in
Port 2 (Datalogging TB2 or printer TB1).
VSD_TX –
Red LED that flashes when transmitting
data out Port 3 to the VSD Logic board.
VSD_RX – Green LED that flashes when receiving
data in Port 3 from the VSD Logic board.
24 VAC power is applied to the 331-03478-xxx
microboard connector J12 and is then used to create the
various DC power sources required by the microboard
circuitry. If the chiller control is malfunctioning,
measure the power supply test points to determine the
status of the microboard.