Tonghui TH2840 Series - Safety Requirement; Insulation Resistance

127
8.3.11.6 Table F Direct Calibrated frequency
20
25
30
40
50
60
80
[Hz]
100
120
150
200
250
300
400
500
600
800
[Hz]
1
1.2
1.5
2
2.5
3
4
5
6
8
[kHz]
10
12
15
20
25
30
40
50
60
80
[kHz]
100
120
150
200
250
300
400
500
600
700
800
900
[kHz]
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
[MHz]
There are 60 frequencies in Table F. The highest frequency of TH2840A/AX/NX up to 500kHz and
the highest frequency of TH2840B/BX up to 2M.
8.3.11.7 Cable length factor K
d
Test signal
level
Cable length
1m
2m
4m
≤2V
rms
2.5×10
-4
（1+50×f
m
）
5×10
-4
（1+50×f
m
）
1×10
-3
（1+50×f
m
）
>2V
rms
2.5×10
-3
（1+16×f
m
）
5×10
-3
（1+16×f
m
）
1×10
-2
（1+16×f
m
）
f
m
：test frequency [MHz]
8.3.11.8 Table G Temperature factor K
e
Temperature (℃)
0 - 18
18 - 28
28 - 40
K
e
4
1
4
8.4 Safety requirement
The instrument is the Ⅰ class safety instrument.
8.4.1 Insulation resistance
Under reference working condition, the insulation resistance between power terminal and
instrument jacket should not be smaller than50MΩ.
Under humility condition, the insulation resistance between voltage terminal and instrument jacket
should not be smaller than 2 MΩ.