Installation and Operation Manual
●
Fan Coil Controller – EZstat
EC-EZstat
Date: 9-2014
Supersedes: NEW
Engineered Comfort reserves the right to change any information concerning product or specification without notice or obligation.
Page 34 of 36
Illustration 8–1 BACnet MS/TP network wiring
The difference between the PID Loop types.
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CL LOOP/HT LOOP - directly controls the fan and modulates off of room temperature
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CL_DAT LOOP/HT_DAT LOOP - modulate to the DAT setpoints. The valves are controlled off these loops.
8.2 Connecting to MS/TP network
Before connecting the EZstat to a BACnet MS/TP network, configure the network properties. See the topic Set up
communications in for the procedure to set the following:
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Device instance
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MAC address
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Baud
Use the following principles when wiring the EZstat to an MS/TP network:
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Connect no more than 128 addressable BACnet devices to one MS/TP network. The devices can be any mix of EZstat
controllers, other BACnet controllers, or BACnet routers.
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To prevent network traffic bottlenecks, limit the MS/TP network size to 60 controllers.
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Use 18 gauge, twisted pair, and shielded cable with capacitance of no more than 51 picofarads per foot for all network
wiring. Belden cable model #82760 meets the cable requirements.
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Connect the ‑A terminal in parallel with all other ‑ terminals. Connect the +B terminal in parallel with all other +
terminals. Connect the shield to an earth ground at one end only.
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Use a KMD‑5575 repeater between every 32 MS/TP devices or if the cable length will exceed 4000 feet (1220 meters).
Use no more than seven repeaters per MS/TP network.
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Place a KMD‑5567 surge suppressor in the cable where it exits a building.
+B
-A
NOTE
Value object
Name
Description
LOOP1
CL LOOP
Cooling Loop
LOOP2
HT LOOP
Heating Loop
LOOP3
CL_DAT LOOP
Cooling Loop
LOOP4
HT_DAT LOOP
Heating Loop
Table 8-9
PID control loops
