DTT-Z / DTR-Z SERIES
ATEX / IECEx Zone 1 Analogue Fixed Telephones
DTT-Z / DTR-Z SERIES
The DTT-Z and DTR-Z Series are ATEX and IECEx certified analogue industrial telephones for installation in Zone 1 and Zone 21 hazardous areas. These fixed hazardous area telephones operate directly from line power, making them suitable for installations where network infrastructure is limited or analogue systems remain in use.
They provide a robust, compliant communication solution for industrial environments requiring dependable voice communication without reliance on VoIP networks.
Key Features
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ATEX and IECEx Zone 1 and Zone 21 certified
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T5 and T6 temperature classifications available
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Line-powered operation (no external power supply required)
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IP66 corrosion resistant housing
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Desk or wall mount configurations
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Direct call ringdown variants
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Optional push-to-talk handset (DTT models)
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2 line backlit LCD display (DTT models)
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Operating temperature range: -30°C to +60°C
Options
• DTT-50-Z – Silicone Keypad/Handset/Heavy duty Curly Cord
• DTT-50-Z-PTT- Silicone Keypad/Handset/Heavy duty Curly Cord/with Push to Talk Handset
• DTT-60-Z – Silicone Keypad/Handset/Armored Cord
• DTR-51-Z – Direct call ringdown/Volume control Handset/Heavy duty Curly Cord
• DTR-61-Z – Direct call ringdown/Volume control Handset/Armored Cord
Electrical Performance
| Parameter | Specification |
|---|---|
| Audible Range Frequency Response | 300 – 3400 Hz |
| Hands Free Speaker Output (DTT-Z Models @ 1KHz) | ~85 dB @ 1 Meter |
| Transmit Objective Loudness Rating (TOLR) | Nominal -38.5 ± 3 dB |
| Receiver Volume Adjustment (DTT-Z) | 8 Steps, 2 dB/Step |
| Receiver Objective Loudness Rating (ROLR) | Nominal 50 ± 3 dB |
| – Receiver Volume at Maximum | 42 ± 3 dB |
| – Receiver Volume at Minimum | 58 ± 3 dB |
| Quick Dial (DTT Models Only) | 10 Registers of 20 Digits Each |
| Flash | 280/600 mSec Timed Disconnect |
| Redial | 31 Digits Maximum |
| Ringer Output | 85 dB @ 1M |
| Ringer Impedance (without Ring Detect Relay) | >7K Ohms @25Hz, 30–90 VAC |
| >4K Ohms @50Hz, 30–90 VAC | |
| Ringer Impedance (with Ring Detect Relay) | >4K Ohms @25Hz, 30–90 VAC |
| (RDR Not Recommended @ 50Hz) | |
| Set Impedance | 600 Ohms Nominal |
| Maximum Loop | 15Kft (~4,600m) of 22 AWG Wire |
| North American Dialling (DTT Models) | DTMF 40:60 Pulse @10 PPS |
| European Dialling (DTT Models) | DTMF or 33:66 Pulse @10 PPS |
| Conforms To | Residential and Industrial Areas |
| ETSI Standards | ETSI TBR 38: May 1998 (Acoustics) |
| ETSI TBR 21: January 1998 (Telephone Network) |
Electrical Requirements
| Parameter | Specification |
|---|---|
| Ringer Sensitivity | 40 – 100 V, 16 – 25 Hz |
| Line Voltage | 24 – 56 VDC |
| Loop Current | DTT-Z: 26 – 100 mA |
| DTR-Z: 20 – 100 mA | |
| Connection Method | Terminal Blocks |
| Fuse – Main Telephone CCT | 250 mA – Auto Reset |
| Ring Detect Relay Contacts (Fused) | 5 Amp 250 VAC Fast Blow |
Mechanical Specifications
| Parameter | Specification |
|---|---|
| Hook Switch (Cradle Switch) Life | >1,000,000 operations |
| Housing Material | High Impact Thermoset Compound |
| Handset Material | High Impact Thermoset Compound |
| Net Weight | 8.68 lbs (3.95 kg) |
| Mechanical Dimensions | 241mm (9.5″) W × 273mm (10.76″) L × 139mm (5.5″) H |
| Shipping Weight | 10.7 lbs (4.9 kg) |
| Shipping Dimensions (L × W × D) | 16.0″ × 10.5″ × 9.5″ (407 × 267 × 242 mm) |
| Mounting | Desk or Wall |
| Microphone | Noise Cancelling |
| Receiver | Hearing Aid Compatible (HAC) |
| Hardware Material | Stainless Steel |
| Wiring Access – DTT-Z Models | 2 × M20 & 1 × M12 Cable Gland Entry Points |
| Wiring Access – DTR-Z Models | 2 × M20 Cable Gland Entry Points |
Environmental
| Parameter | Specification |
|---|---|
| Corrosion Resistance | Full Gasket Faceplate |
| Operating Temperature | -22°F to +140°F (-30°C to +60°C) |
| LCD Note | LCD may become non-responsive below -20°C (-4°F) |
| Ingress Protection Rating | IP66 |
| Humidity | 0 to 95% RH |
Compliance
| Certification | Details |
|---|---|
| IECEx Zone | IECEx EMT 22.0009X |
| ATEX / IECEx Coding (T5) | II 2G Ex eb ib mb IIC T5 Gb |
| II 2D Ex ib mb IIIC T100°C Db | |
| Ambient Range | -30°C ≤ Ta ≤ +60°C |
| ATEX / IECEx Coding (T6) | II 2G Ex eb ib mb IIC T6 Gb |
| II 2D Ex ib mb IIIC T85°C Db | |
| Ambient Range | -30°C ≤ Ta ≤ +45°C |
| ATEX Certificate No. | TRAC09ATEX21205X |
| ATEX Standards | EN IEC 60079-0:2018 |
| EN IEC 60079-7:2015+A1:2018 | |
| EN 60079-11:2012 | |
| EN 60079-18:2015+A1:2017 | |
| IECEx Standards | IEC 60079-0:2017 (Ed. 7.0) |
| IEC 60079-7:2015+A1:2017 (Ed. 5.1) | |
| IEC 60079-11:2011 (Ed. 6.0) | |
| IEC 60079-18:2014+A1:2017 (Ed. 4.1) | |
| Marking | Explosion Protected |
Ordering Information
| Order No. | Description |
|---|---|
| P9051 | DTT-50-Z – Telephone / Silicon Keypad / Volume Control on Keypad / Curly Cord |
| P9052 | DTT-60-Z – Telephone / Silicon Keypad / Volume Control on Keypad / Armored Cord |
| P9053 | DTR-51-Z – Ringdown Telephone / Volume Control on Handset / Curly Cord |
| P9054 | DTR-61-Z – Ringdown Telephone / Volume Control on Handset / Armored Cord |
Options
| Option Code | Description |
|---|---|
| P9066 | DTT-50-Z-PTT – Complete with Push to Talk Handset |
| OA-DTT-PTT | DTT Series Push To Talk handset (disables mic when not in use) |
| 20C-DTT-Zone | 20ft (6.1m) Curly Cord – For DTT-50-Z |
| 20C-DTR-Zone | 20ft (6.1m) Curly Cord – For DTR-51-Z |
| Headsets | Contact Guardian for details |
