Telemark TVP-2000 - Page 64

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TVP Manual (full) March 2007 CE rev 03.doc
4.40 Description of safety systems
Several types of safety devices protect the TVP. These classified into two functional types,
software and hard ware devices. In the scheme of protection the software devices provide first
line protection however in many cases where the rate of change is faster than the electronics
is capable of processing the primary protection is a mechanical device.
Caution
Understanding the hierarchy of system protection is a very useful aid to trouble shooting, each
protection device must be assessed in the case of a forced system shut down.
4.41 Hierarchy and description of protection systems (lowest to highest.)
Software / Electronic protection
1. Coldest temperature prevents cool defrost if too warm.
2. Suction pressure a. Prevents operation below 3 psi system shut down at zero psi.
3. Suction pressure control b. Prevents system start if too low
4. Defrost termination on coil out temperature
5. Defrost termination on time (300 second maximum)
6. Discharge pressure a. Prevents system entering cool, defrost or standby if too high.
7. Discharge pressure b. Terminates defrost if predetermined level exceeded
8. Discharge pressure c. Prevents system switch on if resting pressure limit exceeded.
9. Phase protection determines correct compressor function at start up.
10. Water temperature too high (user adjustable via RS232 commands 20
o
c – 40
o
c) preset
at 35
o
c
11. Full sensor and system continuity and compliance test before start button enabled.
Hardware protection
1. Compressor thermal protection auto-resetting if compressor motor winding maximum
temperature is exceeded.
2. Overload protection immediate shut down of individual compressor if current exceeds
design maximum.
3. Residual current protection (models shipped after 01/06/02) immediate shut down if
leakage to earth detected.
4. Discharge temperature immediate shut down if +145
o
c is exceeded.
5. Discharge pressure immediate shutdown if pressure limit exceeded
Error Code Message displayed Meaning
E1 DP High Discharge pressure too high – limit
varies depending upon operational
state of system
E2 SP Low Suction pressure too low – limit varies
depending upon operational state of
system
E3 WT High Exit water temperature greater than
+35
o
c- user configurable range +20
to +40
o
c
E6 DT High Discharge temperature has exceeded
+145
o
c
E8 Phase Fault Electrical supply is missing or has a
phase reversed.