ELTRA ONH-2000 - Page 68

 2002 by ELTRA GmbH Germany – January 2002 – Service Manual OH 900 / ON 900 / ONH 2000
2.16-2
Detailed explanation of the furnace control system:
GND
GND
12
27
12
1a
2b
GND
7
I C5 on M P 680 00
IC30
-15V
ws
br
TP7
TP13
9
TP8
Ol d V e rs ion :
New Version :
ELECTRONIC RACK
TP1
TP2
PW 1 3
32 066
FUSE 32A
PHASE
FUSE 32A
21
GND
TP10
24+25
12+13
3
2
0
1
5
4
A
8
+15V
TP11
IC3 PIN4
Mult ipli e r
transducer
Current
GND
TP14
power
time
limit
TP2
TP1
RMS
TP 9
+15V
PI N no of th e
bl
gr
br
ws
11
8
gr
W ater f low
W ater flo w
7
15 V m ean s ok
8c
ws
se n so r
Water temp
ge
rs
13
TP3
TP7
PIN4
TP5
TP4
TP13
TP14
IC3
TP8
TP9
TP10
TP12
TP11
TP6
7c
8
I C 29
1V/1kW
37 pin plug
µp Bu s
3
5
Furnace
All JUMPERS on the left row
PW 13 - 32066
Power O FF
Pow e r O N
THYRISTOR
PHASE
circu i t
co nt rol
Mult iplex er
8
10 101k
23
TP14 = 2 to 5 V DC for 2 to 5 kW
TP11 = 0,5 V DC approx.
TP13 = 15 V DC
TP 9 = GND
Prec ond ition s fo r po wer:
blu e
bro wn
yel low
gre y
gre e n
ora n ge
pin k
red
bla ck
vio lett
whit e
bl
br
ge
gr
gn
or
rs
rt
sw
vi
ws
temp sensor
20
19
15
6
15 V m ean s w a t er fl ow
0V m ean s n o w a t er fl ow
9 6 pin plu g
Boa rd MP 6 80 00
Boa rd 68 k
converter
D/A
no flow
0V t o 1 0V f rom th e D/ A co n vert e r
0k W to 10k W on the furnac e
(1V for ea c h kW)
Furnace temperature
0V means too hot
OV m e ans po w e r ON
15 V m ean s p ower O FF
D25 plu g
ON21 see 2.15
THYRISTOR
IC 4 o n 68 k
Flow
1-13 -2
GND