Document: LT0439 Vigilant
MX1-Au
Operator Manual
Issue 1.73
23 October 2018
Page 11-19
Figure 11-15 shows a method of connecting normally energised loads
such as door holders to the ancillary relays, powered from the non-
battery-backed supply VNBF, and with wiring supervision.
This method supervises both supply leads, and can be used with either
ANC1 or ANC2 relays. The two ELDs must have the same value, but
this can be anything between 2.7k
and 27k
. The 18k
or 27k
ELDs
provided with the
MX1
are suitable.
Inductive loads such as door holders must have a suppression diode
connected as shown. A suitable 3A diode is 1N5404.
Note that the ANC1 and ANC2 contacts are rated at 1A inductive at 30V.
The
MX1
must be configured to have the supervision input operate in
“door holder” mode.
If supervision is not required, simply leave off the ELD resistors and the
return wiring to SUP.
Normally
energised loads
E
L
D
E
L
D
ELD values can
be from 2k7-27k,
but must be the
same value
M
X
1
C
O
N
TR
O
LL
E
R
A
N
C
R
E
LA
Y
1
A
N
C
R
E
LA
Y
2
A
N
C
R
E
LA
Y
3
0V
SUP
NC
C
VNBF+
NO
VBF+
Suppression
diode
Figure 11-15 – Wiring to Normally Energised VNBF Loads with Supervision
MX1
has two identical protected inputs which can be used for supervised
connections to clean contacts or open collector style outputs of other
equipment, e.g., sprinkler flow switch. They could also be used for
external fault signals, such as from a power supply or QE90 system.
Figure 11-16 shows examples of connection to normally-open contacts.
IN1 is wired so that short circuit generates a supervision fault. The diode
can be any general purpose silicon diode such as 1N4004. If short circuit
fault supervision is not required, the diode can be omitted, i.e., wired
through.
IN2 is wired to normally-open contacts, which could be an open-collector
output (joins the other equipment to the
MX1
power supply).
Door
Holders
General
Purpose
Inputs (IN1,
IN2)
