IM 689-2
9
The following standard MicroTech applications are supported in the current version of the PMF file:
•
Air-cooled screw chiller (type ALS)
•
Water-cooled screw chiller (types WHS, PFS-B, PFS-C)
•
Air-cooled scroll chiller (type AGZ)
•
Large-tonnage water cooled screw chiller with J&E Hall compressor (type PES)
•
Series-100 centrifugal chiller (old-style MicroTech controls)
•
Series-200 centrifugal chiller
•
Reciprocating chiller (only U.S. manufactured at present)
•
Self-contained air conditioning systems
•
Applied rooftop systems
•
Unit ventilator
•
MicroTech Lead-Lag/Load Balance Panel (LLLB)—
supervisory controller
•
MicroTech Remote Monitoring and Sequencing Panel (RMS)—
supervisory controller
•
MicroTech Remote Monitoring and Control Panel (RMC)—
supervisory controller
•
MicroTech Chiller System Controller (CSC)—
supervisory controller
MicroTech Supervisory Controllers and the Level-2 BACdrop
When a MicroTech supervisory control panel is used (CSC, RMS, RMC, or LLLB), data
transmission speed will be affected. The reason for this is related to the nature of the MicroTech
master-slave network topology.
See figures below. When a MicroTech supervisory controller is not used, the BACdrop gateway is in
the level-1 master position in the MicroTech network. This allows it to obtain data from its level-2
slave controllers in the most efficient way possible. When a MicroTech supervisory controller is used,
it must occupy the level-1 master position, forcing the BACdrop panel to a level-2 slave position.
This means that the level-1 controller (e.g., CSC) must poll the BACdrop for all requests it has of
other controllers (e.g., chiller temperatures) on the network. Because the level-2 BACdrop must wait
to be polled, a delay is introduced that will ultimately affect the responsiveness at the BAS PC. This
delay is minimal—on the order of 1 second per screen of data.
For most applications, a MicroTech supervisory controller is optional. When properly programmed
and installed, a BAS can usually perform the same supervisory control functions that the MicroTech
supervisory controllers perform. One important exception is for the case of a dual-compressor
centrifugal chiller with series-100 (old style) MicroTech controls. For this type of chiller, a
MicroTech supervisory controller—either LLLB or CPC—is
required
to coordinate compressor
operation.
Figure 2. Typical BACdrop Application (Level-1 BACdrop)
RTU
UV
Up to 63 MicroTech
controllers per BACdrop
BACnet on ISO 8802-3 (Ethernet), 10BaseT
MicroTech
BACdrop
(level 1)
Chiller
UV
UV
UV
SCU
Level 2
MicroTech
Level 1
BACnet BAS
by others
Main "front end"
PC for BAS
MicroTech network (RS-485)
