Danfoss SH090 Application Guidelines

20
FRCC.PC.007.B8.02
Application guidelines
Electrical data, connections and wiring
Motor protection
Compressor models SH090-105-120-140-161-184
have been provided with an internal overload
motor protection to prevent against excessive
current and temperature caused by overloading,
low refrigerant  ow or phase loss. The cutout
current is the MCC value listed in section "Three
phase electrical characteristics".
The protector is located in the star point of the
motor and, should it be activated, will cut out all
three phases. It will be reset automatically.
While not compulsory, an additional external
overload is still advisable for either alarm or
manual reset.
Then it must be set below MCC value (at max
operating current:
• when the motor temperature is too high, then
the internal protector will trip
• when the current is too high the external
overload protection will trip before the internal
protection therefore o ering possibility of
manual reset.
Compressor models SH180-240-295-300-
380-485 are delivered with a pre installed
motor protection module inside the terminal
box. This device provides for e cient and
reliable protection against overheating and
overloading (as well as phase loss/reversal on
SH240-295-300-380-485).
The motor protector comprises a control module
and PTC sensors embedded in the motor
winding. The close contact between thermistors
and windings ensures a very low level of thermal
inertia.
The motor temperature is being constantly
measured by a PTC thermistor loop connected
on S1-S2 (called 1-2 on SH180). If any thermistor
exceeds its response temperature, its resistance
increases above the trip level (4,500 Ω) and the
output relay then trips – i.e. contacts M1-M2 (or
11-14 for SH180) are open. After cooling to below
the response temperature (resistance <2,750Ω),
a 5-minute time delay is activated.
After this delay has elapsed, the relay is once
again pulled in – i.e. contacts M1-M2 (11-14
for SH180) are closed. The time delay may be
cancelled by means of resetting the mains (L-N
-disconnect) for approximately 5 sec.
A red/green twin LED is visible on the module.
A solid green LED denotes a fault free condition.
A blinking red LED indicates an identi able fault
condition:
PTC overheat
Appr. 1 second
Delay timer active (after PTC over temp.)
Appr. 1 second
Use a phase meter to establish the phase
orders and connect line phases L1, L2 and L3
to terminals T1, T2 and T3, respectively. The
compressor will only operate properly in a single
direction, and the motor is wound so that if the
connections are correct, the rotation will also be
correct.
Phase sequence and reverse
rotation protection
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Compressor model Overheating protection Over current protection Locked rotor protection Phase reversal protection
SH 090 - 105 - 120 - 140- 161
- 184
Internal motor protection Phase sequence detector recommended
SH 180 Electronic module located in terminal box Reverse vent valve
SH240 - 295 - 300 - 380-485 Electronic module located in terminal box
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Danfoss SH090 Specifications

General

Brand	Danfoss
Model	SH090
Category	Air Compressor
Language	English