Johnson Controls VMA 1420 User Manual

VMA1400 Series Overview and Engineering Guidelines Technical Bulletin 29
Table 18: Additional Detailed VMA Specifications
Feature Specification
Power Input
Voltage Range
20 to 30 VAC; 50 or 60 Hz
Input Current
0.5 Ampere without Relays or Valves
Transient Protection
Isolated from AI, BI, AO, ZBus, +15 VDC and N2 Bus;
Common and Normal Mode Capacitor
N2 Bus Communications
Bus Type and Voltage
RS-485 (Differential
+5 VDC)
Bus Speed
9600 Baud
Transient Protection
Isolated from 24 VAC, BOs, AI, BI, AO, ZBus, +15 VDC;
PTC+Transorb; Common Mode Capacitors
Zone Bus Communications
Bus Type and Voltage
RS-422 (Single-ended 5 VDC) or RS-485 (Differential
+5 VDC)
Bus Speed
1200 Baud
Transient Protection
Isolated from 24 VAC, BOs and N2;
PTC+Transorb; Common Mode Capacitors
Microprocessor/Memory
Microprocessor
8-bit Motorola® 68HC11 operating at 8 MHz
Memory
256 K byte FLASH PROM; 32K byte static RAM
DC Supply Output
Voltage Range
13.5 to 18 VDC
Load Current
0 to 35 mA
Overload and Transient
Protection
Current Foldback; Isolated from 24 VAC, BOs and N2 Bus;
Common Mode Capacitors
Pressure Input
Range
0 to 374 Pascal (0 to 1.5 in. w.c.)
Proof Pressure
6895 Pascal (1 psi)
Burst Pressure
68.9 K Pascal (10 psi)
Resolution (15 bit)
0.0151 Pascal (0.000061 in. w.c.)
Non-Repeatability and
Hysteresis
+0.187 Pascal (+0.00075 in. w.c. maximum)
Non-linearity (Best Fit)
+2 Pascal (+0.008 in. w.c. maximum) for 0-249 Pascal (<1 in. w.c.)
+3 Pascal (0.012 in. w.c. maximum) for >249 Pascal
(>1 in. w.c.)
Thermal Effect on Zero*
+0.1793 Pascal per degree C
(
+0.00040 in. w.c. per degree F maximum)
Thermal Effect on Span
+0.1793 Pascal per degree C
(
+0.00040 in. w.c. per degree F maximum)
Position Effect on Zero*
+0.623 Pascal (+0.0025 in. w.c. maximum)
Position Effect on Full Span
+0.623 Pascal (+0.0025 in. w.c. maximum)
Long Term Zero Drift*
+2.491 Pascal per year (+0.01 in. w.c. per year maximum)
Long Term Span Drift
+2.491 Pascal per year (+0.01 in. w.c. per year maximum)
Sample Time
One second
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Johnson Controls VMA 1420 Specifications

General

Brand	Johnson Controls
Model	VMA 1420
Category	Control Unit
Language	English