ABB REC670 Product Manual page 65

Bay control REC670 2.2
Product version: 2.2.1
Table 41. Thermal overload protection, one time constant LCPTTR/LFPTTR
Function
Reference current
Reference temperature
Operate time:
é
ê
-
2
I I
ê
t
=
t ln
-
ê
T
2 - 2 - Trip
I I
ê
p
ë T
EQUATION13000039 V2 EN-US
T = set operate temperature
Trip
T = ambient temperature
Amb
T = temperature rise above ambient at I
ref
I = reference load current
ref
I = actual measured current
I = load current before overload occurs
p
Alarm temperature
Operate temperature
Reset level temperature
Table 42. Thermal overload protection, two time constants TRPTTR
Function
Base current 1 and 2
Operate time:
æ ö
2 2
-
I I
p
ç ÷
t
= ×
t ln
ç ÷
2 2
-
I I
è ø
ref
(Equation 2)
EQUATION1356 V2 EN-US
I = actual measured current
Ip = load current before overload
occurs
Iref = reference load current
Alarm level 1 and 2
Operate current
Reset level temperature
ABB
Range or value
(2-400)% of IBase
(0-300)°C, (0 - 600)°F
Time constant t = (1–1000)
minutes
ù
ú
2
ú
p
ú
T
Amb × 2
I
ú
ref
û
ref
(Equation 1)
ref
(0-200)°C, (0-400)°F
(0-300)°C, (0-600)°F
(0-300)°C, (0-600)°F
Range or value
IBase
(30–250)% of
I = load current before overload
p
occurs
Time constant τ = (0.10–500.00)
minutes
(50–99)% of heat content
operate value
IBase
(50–250)% of
(10–95)% of heat content trip
M12352-1 v14
Accuracy
±1.0% of I
r
±1.0°C, ±2.0°F
IEC 60255-149, ±5.0% or ±200 ms whichever is greater
±2.0°C, ±4.0°F
±2.0°C, ±4.0°F
±2.0°C, ±4.0°F
M13266-2 v8
Accuracy
±1.0% of I
r
±5.0% or ±200 ms whichever is greater
±2.0% of heat content trip
±1.0% of I
r
±2.0% of heat content trip
1MRK 511 404-BEN A
65