HT instruments HT950N - Manual (Page 5)

HT950N
EN - 5
4. OPERATING INSTRUCTIONS
4.1. DESCRIPTION FRONT PANEL
HT950N
Controller
Fig. 1: Instrument description, frontal view
LEGEND:
1. Principal Display
2. PARAmeters Display
3. SET Display
4. Function keys
 CONTROL Led
The light on of this Led mean that temperature of one of four inputs is over the setting UA
threshold value and the CONTR output relay is closed. This can active the start of forced
ventilation system or a parallel device. The Led light off only when temperature decrease
under UF threshold value and the CONTR relay is open. This can disconnect the forced
ventilation system or a parallel device (see Fig. 9 ).
 PT100 Led
This Led shows that at least one of four controlled input probes (2U, 2V, 2W or 1F Led is
blinking) is shorted or opened. In this case an alarm condition is activated by HT950N and
relay T1 is opened.
 2U-2V-2W-1F Led
These Leds shows, for each of four columns:
 With fixed light means the temperature column you can read on principal display.
 With blinking light, together Pt100 light on, means problems at the correspondent
thermoresistance.
 T1 Led
This Led have the following functions:
 When is light on its shows that temperature of one of four probes is over T1 threshold
set on HT950N and correspondent relay have activated pre-alarm condition (see Fig.
9).
 When is light off, with Pt100 Led fixed light on, its shows one of following conditions:
1. Disconnection of one of four input Pt100 (with correspondent blinking led).
2. One Pt100 is shorted (like point 1.).
3. No one power supply at meter.