MVD safety systems

Below is a schematic of the MVD safety systems. They are grouped according to location (CR, on the floor, in the MVD, in the rack), and according to wether they can operate autonomously or need a functioning computer system. Thus one can see that in the case of a computer (EPICS) failure, the field sensors still can shut things down if a fault is detected. In contrast, the internal temperature and voltage sensors need computer readout in order to effect a (partial) shutdown.

The components and paths in red have already been built and tested. The c-code is a temporary stand-in for EPICS.

Note that we do not use the PLC in this scheme. In the table heading below I added 'or equivalent', which is meant to represent the MVD relay board.

The rack has its own fire and smoke detection, leading to a complete rack shutdown, as can be seen in this diagam of the overall Phenix safety system. The MVD sensors never request a complete rack shutdown, as this would disable all sensors and diagnostics.

The Phenix safety pages can be found here.


postscript version
Links to:

The table below is modeled after this one, requested by Phenix Safety.

item sensor control room alarm
L0 		PLC controller
or equivalent
L1 		trip rack
L2 		Phenix crash
L3 		what is
tripped 		comments
a) MVD East half air and water:
1 T1
East half cooling air supply temperature 		T1>xxx°C 2/3 decision
T1 > xx°C
T2 > xx°C
T3 > xx°C
no no MVD East half Majority decision made by the relay board.
Shutdown decision cuts blower, chiller and LV supplies for the East half.
2 T2
East half plenum air return temperature 		T2>xxx°C
3 T3
East half enclosure air return temperature 		T3>xxx°C
4 F1
East half cooling air supply flow 		F1<xxx l/min 2/3 decision
F1<xxx l/min
F2<xxx l/min
F3<xxx l/min
no no MVD East half Majority decision made by the relay board.
Shutdown decision cuts blower, chiller and LV supplies for the East half.
5 F2
East half plenum air return flow 		F2<xxx l/min
6 F3
East half enclosure air return flow 		F3<xxx l/min
7 H1
East half return air humidity 		Relative Humidity > xx% or < xx% no no no    
8 T4
East half liquid supply temperature 		T4>xx°C 2/2 decision
T4 > xx°C
T5 > xx°C 		no no MVD East half Majority decision made by the relay board.
Shutdown decision cuts liquid pump and LV supplies for the East half.
9 T5
East half liquid return temperature 		T5>xx°C
10 F4
East half liquid supply flow indicator 		F4<xx l/min 2/2 decision
F4<xxx l/min
F5<xxx l/min 		no no MVD East half Majority decision made by the relay board.
Shutdown decision cuts liquid pump and LV supplies for the East half.
11 F5
East half liquid return flow indicator 		F5<xx l/min
b) MVD West half air and water:
12 T6
West half cooling air supply temperature 		T6>xxx°C 2/3 decision
T6 > xx°C
T7 > xx°C
T8 > xx°C
 no no MVD West half Majority decision made by the relay board.
Shutdown decision cuts blower, chillers and LV supplies for the West half.
13 T7
West half plenum air return temperature 		T7>xxx°C
14 T8
West half enclosure air return temperature 		T8>xxx°C
15 F6
West half cooling air supply flow 		F6<xxx l/min 2/3 decision
F6<xxx l/min
F7<xxx l/min
F8<xxx l/min 		no no MVD West half Majority decision made by the relay board.
Shutdown decision cuts blower, chillers and LV supplies for the West half.
16 F7
West half plenum air return flow 		F7<xxx l/min
17 F8
West half enclosure air return flow 		F8<xxx l/min
18 H2
West half return air humidity 		Relative Humidity > xx% or < xx% no no no    
19 T9
West half liquid supply temperature 		T9>xx°C 2/2 decision
T9 >xxx°C
T10>xxx°C 		no no MVD West half Majority decision made by the relay board.
Shutdown decision cuts liquid pump and LV supplies for the West half.
20 T10
West half liquid return temperature 		T10>xx°C
21 F9
West half liquid flow indicator 		F9<xx l/min 2/2 decision
F9<xxx l/min
F10<xxx l/min 		no no MVD West half Majority decision made by the relay board.
Shutdown decision cuts liquid pump and LV supplies for the West half.
22 F10
West half liquid flow indicator 		F10<xxx l/min
c) MVD Motherboard temperatures
23 NW motherboard temperature sensor T>xx°C T>xx°C no no NW motherboard power  
24 NE motherboard temperature sensor T>xx°C T>xx°C no no 6,18...or 36 MCM's
and/or NE motherboard 		 
25 SW motherboard temperature sensor T>xx°C T>xx°C no no 6,18...or 36 MCM's
and/or SW motherboard 		 
26 SE motherboard temperature sensor T>xx°C T>xx°C no no 6,18...or 36 MCM's
and/or SE motherboard 		 
d) MVD Motherboard voltages
27 NW motherboard voltage monitor V<xx V V<xx V no no NW motherboard power  
28 NE motherboard voltage monitor V<xx V V<xx V no no 6,18...or 36 MCM's
and/or NE motherboard 		 
29 SW motherboard voltage monitor V<xx V V<xx V no no 6,18...or 36 MCM's
and/or SW motherboard 		 
30 SE motherboard voltage monitor V<xx V V<xx V no no 6,18...or 36 MCM's
and/or SE motherboard 		 
e) MCM temperatures
31 individual MCM temperature sensor T>xx°C T>xx°C no no 6 MCM's Power is shared by 6 MCM's.
f) radiation monitors
32 8 Si radiation monitors rate>xxx/sec rate>xxx/sec yes? no? Selected Phenix systems (HV, LV...) Only take down systems that can be damaged by radiation in a power-up state.

The actual values for the temperature and flow trip points will have to be evaluated once the entire system is constructed and under test. Some known values are:

Sources:

Last modified 27 Jan 99 HvH, RC
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