GE 239 Instruction Manual page 15

CHAPTER 1: OVERVIEW
239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
Safe Stall Time:................................................1.0 to 600.0 sec
THERMAL MODELING
Thermal Capacity:..........................................separate start/run,
Cool Rate:...........................................................
Stop: ..................................................................1 to 5000 minutes programmable
Run: ...................................................................50% of stopped cool time
Hot/cold: .........................................................50 to 100%, hot after 15 min running
Lockout:...........................................................1 to 5000 min programmable ±20% power on / off
UNBALANCE
Range:..................................................................5 to 100% / OFF
Accuracy: ...........................................................± 2%
Delay: ...................................................................0 - 60 sec
Calculation:
where: I = average phase current
AV
I = current in phase with max dev. from I
M
I = full load current setting
FLC
THERMISTOR
Type: .....................................................................PTC or NTC programmable
Hot Resistance: ...............................................100 to 30 000 Ω
Cold Resistance: ............................................100 to 30 000 Ω
Delay: ...................................................................2 sec
Accuracy: ...........................................................±5% or 100 Ω, whichever is greatest
UNDERCURRENT
Range:..................................................................5 to 100% FLC / OFF
Delay: ...................................................................0 to 250 sec
RTDS (OPTIONAL)
Inputs:..................................................................3 RTDs, stator/bearing prog.
Type: .....................................................................100 Pt (DIN 43760), 100 Ni, 120 Ni, 10 Cu programmable
Range:..................................................................–40 to 200 °C/ –40 to 400 °F
Trip/Alm Range:...............................................0 to 200 °C / 0 to 400 °F
Dead Band:........................................................2 °C / 4 °F
Accuracy: ...........................................................±2 °C / ±4 °F
Lead Resistance:
Pt or Ni RTD:...................................................25 Ω max
Cu RTD:.............................................................3 Ω max
3 wire lead resistance compensation
COMMUNICATIONS
Type: .....................................................................RS485 2 wire, half duplex, isolated
Baud Rate: .........................................................1200 to 19.2k bps
Protocol:..............................................................Modbus
Functions:...........................................................Read/write setpoints, read actual values, execute
exponential cool down
I I
–
M AV
If I ≥ I , UB% -------------------- - × 100
=
AV FLC
I
AV
I I
–
M AV
If I < I , UB% -------------------- - × 100
=
AV FLC
I
FLC
AV
®
RTU
commands
1–9