Power Wiring - Distech Controls ECB-VAV UUKL Installation Manual

Power Wiring

Voltage for UUKL models: 24VAC; ± 15%, Class 2
Voltage for all non-UUKL models: 24VAC/DC; ± 15%, Class 2
This is a Class 2 Product. Use a Class 2 transformer only (rated at 100VA or less at 24VAC) to power the
controller(s).
The Network Guide provides extensive information and requirements for powering a controller that uses a BACnet network for communications. It can be
downloaded from our website. For the ECB-VAV UUKL controller, refer to the guidelines outlined in the Distech Controls UUKL Smoke Control System
Design Guide
It is recommended to wire only one controller per 24VAC transformer.
When calculating a controller's power consumption to size the 24VAC transformer, you must also add the external loads the controller is going to supply,
including the power consumption of any connected subnet module (for example, Allure™ Series Communicating Sensors).
If only one 24VAC transformer is available, determine the maximum number of daisy-chained VAVs that can be supplied on a single power cable sup-
plied by a 100 VA transformer, according to the controller's expected power consumption including external loads, the cable's wire gauge, and the total
cable length from the following figure. Any installation condition that is outside of the parameters of the following graph should be avoided.
To maximize daisy-chaining performance, the transformer should be installed as close as possible to the first VAV. If this is not possible, then use 14
AWG wire to power the first VAV which can help reduce a voltage drop at the end of the daisy-chain.
The recommended minimum peak input voltage is 27.2V
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
100
(30)
Figure 11:
Laboratory testing conditions for the above graph are as follows:
£
Distance between each VAV is evenly spaced along the entire wire length
£
Transformer specification: 100VA (120/24VAC)
£
Tested at room temperature with low voltage line conditions: 108VAC (50Hz)
6 / 18
Daisy Chain Performance
B
A
D
F
C
E
200 300 400
(60) (90) (120)
Total Wire Length in Feet
Maximum Number of VAV Devices on a Daisy-Chain at Evenly Spaced Intervals
p
A
VAV + SmartVue (AWG18)
B
VAV + SmartVue (AWG16)
C
VAV + SmartVue + 2DO (1,6VA each) (AWG18)
D
VAV + SmartVue + 2DO (1,6VA each) (AWG16)
E
VAV + SmartVue + SmartVue CO2 + 2DO (1,6VA each) (AWG18)
F VAV + SmartVue + SmartVue CO2 + 2DO (1,6VA each) (AWG16)
500 600
(150) (180) (210)
(meters)
700 800 900
(240) (270)
1000
(300)