EngA ENGINEERED AIR DJM2.4, Инструкция по установке, эксплуатации и обслуживанию, Страница: 13 / 37

DJM2.4 MANUAL
13 Oct 00 R2
XI. BMS CONTROL
See Section XII for information on BMS control wiring connections. Note the comments under the
following headings if a BMS or other DCV control device is connected to the DJM2.

"W
IRING
" (See section IV)

"P
ROPORTIONAL
/I
NTEGRAL
S
ETTING
" (See section VI and X)

"T
EMPERATURE
C
ONTROL
" (See section XI)

"BMS C
ALIBRATION AND
S
ET
U
P
" (See section XII and X)
BMS can be wired into either of the following two sets of terminals.
BMS W
IRED TO
"R"
AND
"W" (Use Only on Retrofitting Old DJM)
If the DJM2 is to be directly controlled by a building management control system using current or
voltage, and that signal is wired through a resistor network into terminals R and W, the control
power to H and N MUST come from an isolated and ungrounded transformer. This resistor
network is to reduce the input voltage to a 0-3.5 VDC signal. The control power to H and N must
come from an isolated and ungrounded transformer. The power to terminals HS and 3 must come
from the same power source as applied to terminal H. This will require an isolating relay be used.
As the DJM2 also has a set of true 0-10 VDC input terminals, it is best to use them instead of this
option (R and W terminals are not optically isolated).
BMS Wired Into "+" and "-" (Preferred Method)
If desired, the wiring may be changed such that the BMS or control voltage is wired to terminals “+
and -”. These terminals are optically isolated and will eliminate the requirements for a separate
ungrounded isolating transformer. The control providing the signal to the “+ and -” terminals needs
to be a 0-10 VDC signal that has capability of a 20 ma or stronger drive.
For new installations we recommend using terminals “+ and -”.
Remote wiring should be run using minimum size 22 ga shielded wire. For runs over 150 feet, the
use of minimum wire size of 20 ga-shielded wire is recommended. The shield should be grounded
at the controller end only. If the shield is grounded in more then one place then the shield is made
useless between the two grounds. Input impedance is 500 ohms. If the control driving the DJM2
cannot output enough power to drive the DJM2, then resistor R19
(680 ohms) located on the back
of the board (near the +/- terminals) will need to be cut. This will give 1500 ohm input impedance.
Not being able to drive is recognized by seeing an output from the BMS to the DJM2 of 10 VDC
when not connected but measuring much less at the DJM2 + and

terminals when connected.
For new installations we recommend using terminals “+ and -”.
All DJM2 relay contacts are rated at 5 amps. The TRIAC output (combustion blower) will handle a
0.6 HP motor at 120 vac.
XII. BMS CALIBRATION AND SET UP
See section V about types of BMS control and set-up. If wired to a building
Comparison
(VDC) (MA)